diff --git a/admin_user.h b/admin_user.h
index fbc1ed0..88595fa 100644
--- a/admin_user.h
+++ b/admin_user.h
@@ -43,7 +43,7 @@ void admin_menu(){
     char welcome[256];
     bool exit = false;
     do{
-        sprintf(welcome,"welcome %s(%s)",user->name,user->role);
+        sprintf(welcome,"welcome %s(%s)\n",user->name,user->role);
 
         switch (choices_selecter(Items,4,welcome))
         {
@@ -79,27 +79,28 @@ struct user_row *prompt_user(){
     if(user_id == 0){
         printf("cancelled\n");
         printf("press any key to continue\n");
-        fflush(stdin);
+        fflush_stdin();
         getchar();
         return NULL;
     }
     struct user_row *user = get_user(user_id);
+    Cls();
     if(user == NULL){
         printf("User not found\n");
         printf("press any key to continue\n");
-        fflush(stdin);
+        fflush_stdin();
         getchar();
         return NULL;
     }else if(!is_admin(user->role)){
         printf("You aren't an admin\n");
         printf("press any key to continue\n");
-        fflush(stdin);
+        fflush_stdin();
         getchar();
         return NULL;
     }else{
-        printf("Welcome %s(%s)\n", user->name,user->role);
+            printf("Welcome %s %s\n", user->name , user->role);
         printf("press any key to continue\n");
-        fflush(stdin);
+        fflush_stdin();
         getchar();
     }
     return user;
@@ -131,14 +132,13 @@ void inv_control(){
                 db.db.row_count += 1;
                 strcpy(db.row[db.db.row_count - 1].product,"CREATE NEW ITEM");
                 db.row[db.db.row_count - 1].barcode = -1024;//IMPORTANT: -1024 is reserved for new item
-                char * SortItemss[] = {
+                char * SortItems[] = {
                     "Name",
                     "Price",
                     "Brand",
                     "Category",
                 };
-                lister(&db,NULL,db.db.row_count,"Inventory",SortItemss,4,Print_page,SortItems,item_control);
-                // list_page(db,NULL,db.db.row_count,item_control);
+                lister(&db,NULL,db.db.row_count,"Inventory",SortItems,4,print_page,sortItems,item_control);
                 break;
             case 2://add item
                 add_item();
@@ -229,7 +229,7 @@ void add_item(){
         printf("Item added\n");
     }
     printf("press any key to continue\n");
-    fflush(stdin);
+    fflush_stdin();
     getchar();
 }
 
@@ -254,7 +254,7 @@ void update_item(struct inventory db,int index){
         printf("Item updated\n");
     }
     printf("press any key to continue\n");
-    fflush(stdin);
+    fflush_stdin();
     getchar();
 }
 
@@ -262,7 +262,7 @@ void remove_item(struct inventory db,int index){
     printf("Remove item\n");
     printf("Are you sure you want to remove this item? (y/n)\n");
     char choice;
-    fflush(stdin);
+    fflush_stdin();
     scanf("%c", &choice);
     db.row[index].isdeleted = true;
     if(choice == 'y'){
@@ -275,7 +275,7 @@ void remove_item(struct inventory db,int index){
         printf("Item not removed\n");
     }
     printf("press any key to continue\n");
-    fflush(stdin);
+    fflush_stdin();
     getchar();
 }
 
@@ -293,6 +293,13 @@ void tran_control(){
         choice = choices_selecter(items,2,"><Welcome to the Student Union POS system><\nTransaction control");
         switch(choice){
              case 1:
+                char * SortItems[] = {
+                    "Date&Time",
+                    "product(barcode)",
+                    "quantity",
+                    "total",
+                };
+                lister(&tran,NULL,tran.db.row_count,"Transaction list",SortItems,4,print_tran,sortTrans,showTran);) 
                 list_tran(tran);
                 break;
             case 2:
@@ -348,7 +355,7 @@ void list_tran(struct transaction db){
     do{
         valid = true;
         printf("Please input your choice\n>");
-        fflush(stdin);
+        fflush_stdin();
         scanf("%d",&choice);
          if(choice <=8 && choice > 0){
             printf("sorting...\n");
@@ -369,7 +376,7 @@ void list_tran(struct transaction db){
             }
         }else if(choice == current_page_size+3){
             printf("Enter page size: ");
-            fflush(stdin);
+            fflush_stdin();
             scanf("%d", &page_size);
             total_pages = ceil((double)row / page_size);
         }else if(choice >= 9 && choice <= current_page_size){
@@ -436,7 +443,7 @@ struct transaction showTran(struct transaction db,int index){
     bool valid = true;
     do{
         printf("Please input your choice: ");
-        fflush(stdin);
+        fflush_stdin();
         scanf("%d",&choice);
         switch(choice){
             case 1:
@@ -466,7 +473,7 @@ void add_tran(){
     struct transaction_row* row = (struct transaction_row*)malloc(sizeof(struct transaction_row));
     char check;
     printf("Use current date time? (y/n): ");
-    fflush(stdin);
+    fflush_stdin();
     scanf("%c",&check);
     if(check == 'y'){
         row->date = get_date();
@@ -498,7 +505,7 @@ void add_tran(){
         printf("Item added\n");
     }
     printf("press any key to continue\n");
-    fflush(stdin);
+    fflush_stdin();
     getchar();
 
 
@@ -531,7 +538,7 @@ struct transaction update_tran(struct transaction db,int index){
         printf("Transaction updated\n");
     }
     printf("press any key to continue\n");
-    fflush(stdin);
+    fflush_stdin();
     getchar();
 
     return db;
@@ -546,7 +553,7 @@ struct transaction remove_tran(struct transaction db,int index){
         printf("Transaction deleted\n");
     }
     printf("press any key to continue\n");
-    fflush(stdin);
+    fflush_stdin();
     getchar();
 
     return read_db_tran();
@@ -619,7 +626,7 @@ void user_control(){
         printf("2. List User\n");
         printf("3. Exit\n");
         printf("Please input your choice\n>");
-        fflush(stdin);
+        fflush_stdin();
         scanf("%d",&choice);
         switch(choice){
             case 1:
@@ -633,7 +640,7 @@ void user_control(){
             default:
                 printf("Invalid choice\n");
                 printf("press any key to continue\n");
-                fflush(stdin);
+                fflush_stdin();
                 getchar();
                 break;
         }
@@ -660,7 +667,7 @@ struct user add_user(struct user db){
         printf("User added\n");
     }
     printf("press any key to continue\n");
-    fflush(stdin);
+    fflush_stdin();
     getchar();
 
     return read_db_user();
@@ -681,7 +688,7 @@ struct user edit_user(struct user db,int index){
         printf("User updated\n");
     }
     printf("press any key to continue\n");
-    fflush(stdin);
+    fflush_stdin();
     getchar();
 
     return db;
@@ -695,7 +702,7 @@ struct user delete_user(struct user db,int index){
         printf("User deleted\n");
     }
     printf("press any key to continue\n");
-    fflush(stdin);
+    fflush_stdin();
     getchar();
 
     return read_db_user();
@@ -738,7 +745,7 @@ struct user list_user(struct user db){
     do{
         valid = true;
         printf("Please input your choice\n>");
-        fflush(stdin);
+        fflush_stdin();
         scanf("%d",&choice);
         if(choice <=6 && choice > 0){
             printf("sorting...\n");
@@ -759,7 +766,7 @@ struct user list_user(struct user db){
             }
         }else if(choice == current_page_size+3){
             printf("Enter page size: ");
-            fflush(stdin);
+            fflush_stdin();
             scanf("%d", &page_size);
             total_pages = ceil((double)row / page_size);
         }else if(choice >= 7 && choice <= current_page_size){
@@ -782,6 +789,7 @@ void print_user(struct user db, int cur, int end,struct Map* map){
     for(int i = cur; i < end; i++){
         if(map == NULL){
             bool isadmin = is_admin(db.row[i].role);
+            // printf("isadmin%s\n",db.row[i].id);
             printf("%-5d%-20s%-10ld%-10s%-10c\n",i+7,db.row[i].name,db.row[i].id,db.row[i].role,isadmin?'Y':'N');
         }else{
             int index = map[i].key;
@@ -850,7 +858,7 @@ struct user showUser(struct user db,int index){
         printf("1 edit user\n");
         printf("2 delete user\n");
         printf("Enter choice: ");
-        fflush(stdin);
+        fflush_stdin();
         scanf("%d", &choice);
         switch (choice){
             case 0:
@@ -864,7 +872,7 @@ struct user showUser(struct user db,int index){
             default:
                 printf("Invalid choice\n");
                 printf("press any key to continue\n");
-                fflush(stdin);
+                fflush_stdin();
                 getchar();
                 break;
         }
@@ -904,18 +912,18 @@ void role_control(){
 void add_role(){
     char role[100];
     printf("Enter Admin role name: ");
-    fflush(stdin);
+    fflush_stdin();
     scanf("%s", role);
     if(is_admin(role)){//check if role exist in admin file
         printf("Admin role already exist\n");
         printf("press any key to continue\n");
-        fflush(stdin);
+        fflush_stdin();
         getchar();
     }else{
         add_admin(role);
         printf("role added\n");
         printf("press any key to continue\n");
-        fflush(stdin);
+        fflush_stdin();
         getchar();
     }
     return;
@@ -962,7 +970,7 @@ void list_role(){
         do{
             valid = true;
             printf("Please input your choice\n>");
-            fflush(stdin);
+            fflush_stdin();
             scanf("%d", &choice);
             if(choice <=4 && choice > 0){
                 printf("sorting...\n");
@@ -983,7 +991,7 @@ void list_role(){
                 }
             }else if(choice == current_page_size+3){
                 printf("Enter page size: ");
-                fflush(stdin);
+                fflush_stdin();
                 scanf("%d", &page_size);
                 total_pages = ceil( (double)list_size / page_size);
                 page = 0;
@@ -1032,7 +1040,7 @@ void showRole(struct linkedlist* list,int index){
     do{
         valid = true;
         printf("Please input your choice\n>");
-        fflush(stdin);
+        fflush_stdin();
         scanf("%d", &choice);
         if(choice == 1){
             if(is_admin(name)){
@@ -1042,7 +1050,7 @@ void showRole(struct linkedlist* list,int index){
             }
             printf("Admin role toggled\n");
             printf("Press any key to continue\n");
-            fflush(stdin);
+            fflush_stdin();
             getchar();
         }else if(choice != 2){
             printf("Invalid choice\n");
diff --git a/database.h b/database.h
index 09507e5..40ae4f9 100644
--- a/database.h
+++ b/database.h
@@ -127,7 +127,7 @@ bool is_admin(char* role){
     while(fgets(line,100,fp) != NULL){
         if(line[0] == '#') continue;
 
-        if(line[strlen(line)-1] == '\n')
+        while(line[strlen(line)-1] == '\n' || (int)line[strlen(line)-1] == 13)
             line[strlen(line)-1] = '\0';
         
         if(strcmp(line,role) == 0){
@@ -169,7 +169,7 @@ void remove_admin(char* role){
             fprintf(fp2,"%s",line);
             continue;
         }
-        if(line[strlen(line)-1] == '\n')//remove newline for compare
+        while(line[strlen(line)-1] == '\n' || (int)line[strlen(line)-1] == 13)//remove newline for compare
             line[strlen(line)-1] = '\0';
         if(strcmp(line,role) != 0){
             fprintf(fp2,"%s\n",line);
@@ -222,10 +222,12 @@ struct inventory read_db_invt(){//please open file in read mode
             if(buffer[0] == '#'){//catch comment line and ignore
                 j--;//decrement j to prevent skipping next column
             }else{
-
-                if(buffer[strlen(buffer)-1] == '\n')
+                buffer[strlen(buffer)] = '\0';
+                while(buffer[strlen(buffer)-1] == '\n' || (int)buffer[strlen(buffer)-1] == 13){
                     buffer[strlen(buffer)-1] = '\0';
 
+                }
+
                 switch(j){
                     case category:
                         strcpy(db.row[i].category,buffer);
@@ -282,9 +284,12 @@ struct transaction read_db_tran(){
             if(buffer[0] == '#'){//catch comment line and ignore
                 j--;//decrement j to prevent skipping next column
             }else{
-                if(buffer[strlen(buffer)-1] == '\n')
+                buffer[strlen(buffer)] = '\0';
+                while(buffer[strlen(buffer)-1] == '\n' || (int)buffer[strlen(buffer)-1] == 13){
                     buffer[strlen(buffer)-1] = '\0';
 
+                }
+
                 switch(j){
                     case date:
                         db.row[i].date = convert_to_date(buffer);
@@ -338,9 +343,12 @@ struct user read_db_user(){
             if(buffer[0] == '#'){//catch comment line and ignore
                 j--;//decrement j to prevent skipping next column
             }else{
-                if(buffer[strlen(buffer)-1] == '\n')
+                buffer[strlen(buffer)] = '\0';//prevent any garbage value
+                while(buffer[strlen(buffer)-1] == '\n' || (int)buffer[strlen(buffer)-1] == 13){
                     buffer[strlen(buffer)-1] = '\0';
 
+                }
+
                 switch(j){
                     case name:
                         strcpy(db.row[i].name,buffer);
@@ -732,7 +740,8 @@ struct user_row* get_user(long userid){
             if(buffer[0] == '#'){//catch comment line and ignore
                 j--;//decrement j to prevent skipping next column
             }else{
-                if(buffer[strlen(buffer)-1] == '\n'){
+                buffer[strlen(buffer)] = '\0';
+                while(buffer[strlen(buffer)-1] == '\n' || (int)buffer[strlen(buffer)-1] == 13){
                     buffer[strlen(buffer)-1] = '\0';
                 }
 
diff --git a/main.c b/main.c
index aea56e7..7bd1131 100644
--- a/main.c
+++ b/main.c
@@ -51,7 +51,7 @@ int main(){
             break;
         }
 
-        fflush(stdin);
+        fflush_stdin();
     } while (check);
     
     return 0;
diff --git a/normal_user.h b/normal_user.h
index aaf9851..4f8a841 100644
--- a/normal_user.h
+++ b/normal_user.h
@@ -25,7 +25,8 @@
 void list_items();
 void search_item();
 void self_help_sale_system();
-void print_page(struct inventory db, int cur, int end,struct Map* map);
+void print_page(void * ddb, int cur, int end,struct Map* map);
+struct Map* sortItems(void * ddb, int sort);
 
 //main of normal user
 void normal_menu(){
@@ -55,8 +56,8 @@ void normal_menu(){
 }
 
 //universal functions for normal user
-struct Map* sortItems(struct inventory db, int sort);
-struct inventory show_item(struct inventory db,int index){
+void * show_item(void * ddb,int index){
+    struct inventory db = *((struct inventory*)ddb);
     Cls();
     printf("Product: %s\n", db.row[index].product);
     printf("Catergory: %s\n", db.row[index].category);
@@ -65,105 +66,105 @@ struct inventory show_item(struct inventory db,int index){
     printf("Stock: %d\n", db.row[index].stock);
     printf("Barcode: %ld\n",db.row[index].barcode);
     printf("Press any key to return to the list\n");
-    fflush(stdin);
+    fflush_stdin();
     getchar();
-    return db;
+    return ddb;
 }
 
 //user for showing list result and search result
-void list_page(struct inventory db,struct Map* map,int row,struct inventory (*showitem)(struct inventory,int)){//showitem is a function pointer for showing item,allow customization for better flexibilty  
-    int choice = -1;
-    int page = 0;
-    int page_size = PAGE_SIZE;
-    int total_pages = ceil((double)row / page_size);
-    do{
+// void list_page(struct inventory db,struct Map* map,int row,struct inventory (*showitem)(struct inventory,int)){//showitem is a function pointer for showing item,allow customization for better flexibilty  
+//     int choice = -1;
+//     int page = 0;
+//     int page_size = PAGE_SIZE;
+//     int total_pages = ceil((double)row / page_size);
+//     do{
 
-    //options
-    Cls();
-    printf("0 exit\n");
-    printf("1 sort name decending\n");
-    printf("2 sort name ascending\n");
-    printf("3 sort price decending\n");
-    printf("4 sort price ascending\n");
-    printf("5 sort brand decending\n");
-    printf("6 sort brand ascending\n");
-    printf("7 sort category decending\n");
-    printf("8 sort category ascending\n");
-    printf("List of items:\n");
+//     //options
+//     Cls();
+//     printf("0 exit\n");
+//     printf("1 sort name decending\n");
+//     printf("2 sort name ascending\n");
+//     printf("3 sort price decending\n");
+//     printf("4 sort price ascending\n");
+//     printf("5 sort brand decending\n");
+//     printf("6 sort brand ascending\n");
+//     printf("7 sort category decending\n");
+//     printf("8 sort category ascending\n");
+//     printf("List of items:\n");
 
-    //print items
-    if(page + 1 >= total_pages){
-        print_page(db, page * page_size, row,map);
-    }else{
-        print_page(db, page * page_size, (page + 1) * page_size,map);
-    }
+//     //print items
+//     if(page + 1 >= total_pages){
+//         print_page(db, page * page_size, row,map);
+//     }else{
+//         print_page(db, page * page_size, (page + 1) * page_size,map);
+//     }
 
-    //page control
-    int current_page_size = 8 + page_size;
-    if(page + 1 >= total_pages){
-        current_page_size = row - page * page_size+8;
-    }
-    printf("%d next page\n", current_page_size+1);
-    printf("%d previous page\n", current_page_size+2);
-    printf("%d set page size\n", current_page_size+3);
-    printf("%d/%d/%d(page size/page number/total)\n",page_size, page+1,total_pages);
+//     //page control
+//     int current_page_size = 8 + page_size;
+//     if(page + 1 >= total_pages){
+//         current_page_size = row - page * page_size+8;
+//     }
+//     printf("%d next page\n", current_page_size+1);
+//     printf("%d previous page\n", current_page_size+2);
+//     printf("%d set page size\n", current_page_size+3);
+//     printf("%d/%d/%d(page size/page number/total)\n",page_size, page+1,total_pages);
 
-    //prompt user to select an item
-    bool valid = true; 
-    do{
-        valid = true;
-        printf("Enter your choice: ");
-        fflush(stdin);
-        scanf("%d", &choice);
-        if(choice <=8 && choice > 0){
-            printf("sorting...\n");
-            map = sortItems(db,choice);
-        }else if(choice == current_page_size+1 ){
-            if(page + 1 < total_pages){
-                page++;
-            }else{
-                printf("Already at last page\n");
-                valid = false;
-            }
-        }else if(choice == current_page_size+2){
-            if(page > 0){
-                page--;
-            }else{
-                printf("Already at first page\n");
-                valid = false;
-            }
-        }else if(choice == current_page_size+3){
-            printf("Enter page size: ");
-            fflush(stdin);
-            scanf("%d", &page_size);
-            total_pages = ceil((double)row / page_size);
-        }else if(choice >= 9 && choice <= current_page_size){
-            if(map == NULL){
-                db = (*showitem)(db,choice - 9 + page_size*page);
-            }else{
-                db = (*showitem)(db,map[choice - 9 + page_size*page].key);
-            }
-        }else if(choice != 0){
-            printf("Invalid choice\n");
-            valid = false;
-        }
-    }while(!valid);
+//     //prompt user to select an item
+//     bool valid = true; 
+//     do{
+//         valid = true;
+//         printf("Enter your choice: ");
+//         fflush_stdin();
+//         scanf("%d", &choice);
+//         if(choice <=8 && choice > 0){
+//             printf("sorting...\n");
+//             map = sortItems(db,choice);
+//         }else if(choice == current_page_size+1 ){
+//             if(page + 1 < total_pages){
+//                 page++;
+//             }else{
+//                 printf("Already at last page\n");
+//                 valid = false;
+//             }
+//         }else if(choice == current_page_size+2){
+//             if(page > 0){
+//                 page--;
+//             }else{
+//                 printf("Already at first page\n");
+//                 valid = false;
+//             }
+//         }else if(choice == current_page_size+3){
+//             printf("Enter page size: ");
+//             fflush_stdin();
+//             scanf("%d", &page_size);
+//             total_pages = ceil((double)row / page_size);
+//         }else if(choice >= 9 && choice <= current_page_size){
+//             if(map == NULL){
+//                 db = (*showitem)(db,choice - 9 + page_size*page);
+//             }else{
+//                 db = (*showitem)(db,map[choice - 9 + page_size*page].key);
+//             }
+//         }else if(choice != 0){
+//             printf("Invalid choice\n");
+//             valid = false;
+//         }
+//     }while(!valid);
 
-    }while(choice != 0);
-}
+//     }while(choice != 0);
+// }
 //print the list for the page
-void print_page(struct inventory db, int cur, int end,struct Map* map){
-    for (int i = cur; i < end; i++)
-    {
-        if(map != NULL){
-            printf("%d item %d: %s\n", i + 9,i, db.row[map[i].key].product);
-        }
-        else{
-            printf("%d item %d: %s\n", i + 9,i, db.row[i].product);
-        }
-    }
-}
-void Print_page(void * ddb, int cur, int end,struct Map* map){
+// void print_page(struct inventory db, int cur, int end,struct Map* map){
+//     for (int i = cur; i < end; i++)
+//     {
+//         if(map != NULL){
+//             printf("%d item %d: %s\n", i + 9,i, db.row[map[i].key].product);
+//         }
+//         else{
+//             printf("%d item %d: %s\n", i + 9,i, db.row[i].product);
+//         }
+//     }
+// }
+void print_page(void * ddb, int cur, int end,struct Map* map){
     struct inventory db = *((struct inventory*)ddb);
     for (int i = cur; i < end; i++)
     {
@@ -194,66 +195,12 @@ void list_items(){
         "Brand",
         "Category",
     };
-    // FIXME:function for normal list page
-    // lister(&db,map,db.db.row_count,"List of items",SortItems,4,print_page,sortItems,item_control);
-    list_page(db,map,db.db.row_count,show_item);
+    lister(&db,map,db.db.row_count,"List of items",SortItems,4,print_page,sortItems,show_item);
 }
 
 //for sorting
-struct Map* sortItems(struct inventory db, int sort){
-// struct Map* sortItems(void * ddb, int sort){
-//     struct inventory db = *((struct inventory*)ddb);
-    struct Map *map = malloc(sizeof(struct Map) * db.db.row_count-1);
-    for (int i = 0; i < db.db.row_count-1; i++){
-        map[i].key = i;
 
-        switch(sort){
-            case 1:
-            case 2:
-                map[i].value = (void*)db.row[i].product;
-                break;
-
-            case 3:
-            case 4:;
-                double price = db.row[i].price * 100;
-                double * price_star = malloc(sizeof(long));
-                *price_star = price;
-                map[i].value = (void*)price_star;//presume there is no price contain  0.001
-                break;
-            case 5:
-            case 6:
-                map[i].value = (void*)db.row[i].brand;
-                break;
-            case 7:
-            case 8:
-                map[i].value = (void*)db.row[i].category;
-                break;
-        }
-    }
-    switch (sort){
-        case 1:
-        case 5:
-        case 7:
-            qsort(map, db.db.row_count-1, sizeof(struct Map), compare_decending_str);
-            break;
-        case 2:
-        case 6:
-        case 8:
-            qsort(map, db.db.row_count-1, sizeof(struct Map), compare_ascending_str);
-            break;
-        case 3:
-            qsort(map, db.db.row_count-1, sizeof(struct Map), compare_decending);
-            break;
-        case 4:
-            qsort(map, db.db.row_count-1, sizeof(struct Map), compare_ascending);
-            break;
-    }
-    map = realloc(map, sizeof(struct Map) * db.db.row_count);
-    map[db.db.row_count-1].key = db.db.row_count-1;
-    return map;
-}
-
-struct Map* SortItems(void * ddb, int sort){
+struct Map* sortItems(void * ddb, int sort){
     struct inventory db = *((struct inventory*)ddb);
     struct Map *map = malloc(sizeof(struct Map) * db.db.row_count-1);
     for (int i = 0; i < db.db.row_count-1; i++){
@@ -332,19 +279,17 @@ void search_item(){
     map = searchItems(db,searchstr);
     if(map[0].value > 0){
         int temp_row = *((int*)map[0].value);
-        // char * SortItems[] = {
-        //     "Name",
-        //     "Price",
-        //     "Brand",
-        //     "Category",
-        // };
-        //FIXME
-        // lister(&db,map+1,temp_row,"List of items",SortItems,4,print_page,sortItems,item_control);//ofset map, as it is use to store the size
-        list_page(db,map+1,temp_row,show_item);//ofset map, as it is use to store the size
+        char * SortItems[] = {
+            "Name",
+            "Price",
+            "Brand",
+            "Category",
+        };
+        lister(&db,map+1,temp_row,"List of items",SortItems,4,print_page,sortItems,show_item);//ofset map, as it is use to store the size
     }else{//empty search
         printf("No result found\n");
         printf("Press any key to continue\n");
-        fflush(stdin);
+        fflush_stdin();
         getchar();
 
     }
@@ -356,7 +301,7 @@ void search_item(){
 char* prompt_search(){
     printf("Enter search string:(largest length 100)(case insesitive)\n");
     char* searchstr = malloc(sizeof(char) * 100);
-    fflush(stdin);
+    fflush_stdin();
     scanf("%s", searchstr);
     return searchstr;
 }
@@ -521,23 +466,23 @@ struct cart* scan_barcode(struct cart* cart,struct inventory db){
             printf("product: %s\n",row->product);
             printf("price: %.1f\n",row->price);
             printf("Enter quantity(0 to cancel)\n>");\
-            fflush(stdin);
+            fflush_stdin();
             scanf("%d", &quantity);
-            fflush(stdin);
+            fflush_stdin();
             if(quantity == 0){
                 printf("cancelled\n");
                 printf("press any key to continue\n");
-                fflush(stdin);
+                fflush_stdin();
                 getchar();
                 return cart;
             }
             printf("Are you sure you want to add this item to cart?(y/n)\n>");
-            fflush(stdin);
+            fflush_stdin();
             scanf("%c", &choice);
             if(row->stock - quantity < 0 && choice == 'y'){
                 printf("WARNING:not enough stock\n");
                 printf("Are you sure the quantity is correct?\n(y to ignore and continue/n)\n>");
-                fflush(stdin);
+                fflush_stdin();
                 scanf("%c", &choice);
             }
         }while(choice != 'y');
@@ -550,7 +495,7 @@ struct cart* scan_barcode(struct cart* cart,struct inventory db){
 
     }
     printf("press any key to continue\n");
-    fflush(stdin);
+    fflush_stdin();
     getchar();
     return cart;
 }
@@ -559,7 +504,7 @@ struct cart* scan_barcode(struct cart* cart,struct inventory db){
 long prompt_barcode(){
     printf("Please scan the qr code(or input the barcode ) ");
     long barcode;
-    fflush(stdin);
+    fflush_stdin();
     scanf("%ld", &barcode);
     return barcode;
 }
@@ -611,7 +556,7 @@ struct cart* list_cart(struct cart* cart){
         }
         do{
             printf("input the corresponding value for more action\n>");
-            fflush(stdin);
+            fflush_stdin();
             scanf("%d", &choice);
             if(choice >0 && choice < i){
                 cart = cart_control(cart,choice);
@@ -644,13 +589,13 @@ struct cart* cart_control(struct cart* cart,int index){
                 cart = Cartremove(cart,index-1);
                 printf("Remove successful\n");
                 printf("press any key to continue\n");
-                fflush(stdin);
+                fflush_stdin();
                 getchar();
             }else if(choice == 2){
                 cart = update_cart(cart,index);
                 printf("Update successful\n");
                 printf("press any key to continue");
-                fflush(stdin);
+                fflush_stdin();
                 getchar();
             }
     }while(choice != 1 || choice != 2 || choice !=3 );
@@ -664,10 +609,10 @@ struct cart* update_cart(struct cart* cart,int index){
     do{
         int quantity = 0;
         printf("enter the new quantity: ");
-        fflush(stdin);
+        fflush_stdin();
         scanf("%d", &quantity);
         printf("Are you sure you want to update this item?(y/n/e to exit)");
-        fflush(stdin);
+        fflush_stdin();
         scanf("%c", &choice);
         if(choice == 'y'){
             
@@ -695,7 +640,7 @@ struct cart* checkout(struct cart* cart){
     if(user_id == 0){
         printf("cancelled\n");
         printf("press any key to continue\n");
-        fflush(stdin);
+        fflush_stdin();
         getchar();
         return cart;
     }
@@ -705,33 +650,33 @@ struct cart* checkout(struct cart* cart){
     if(user == NULL){
         printf("Fail to indentify your card or error occurs\n");
         printf("press any key to continue\n");
-        fflush(stdin);
+        fflush_stdin();
         getchar();
         return cart;
     }else{
         printf("Welcome %s(%s)\n",user->name,user->role);
         printf("Are you sure you want to checkout?(y/n)\n>");
         char choice;
-        fflush(stdin);
+        fflush_stdin();
         scanf("%c", &choice);
         if(choice == 'y'){
             if(update_stock_N_checkout(cart,user)){//catch err
                 printf("Checkout successful\n");
                 printf("press any key to continue\n");
-                fflush(stdin);
+                fflush_stdin();
                 getchar();
                 return NULL;
             }else{
                 printf("Checkout failed(files maybe corrputed)\n");
                 printf("press any key to continue\n");
-                fflush(stdin);
+                fflush_stdin();
                 getchar();
                 return cart;
             }
         }else{
             printf("cancelled\n");
             printf("press any key to continue\n");
-            fflush(stdin);
+            fflush_stdin();
             getchar();
             return cart;
         }
diff --git a/utils.h b/utils.h
index 86d9678..50de476 100644
--- a/utils.h
+++ b/utils.h
@@ -9,7 +9,10 @@
 #include<ctype.h>
 #include <stddef.h>
 #endif
-
+#ifdef _WIN32
+#else
+#include <stdio_ext.h>
+#endif
 void Cls(){
     #ifdef _WIN32
         system("cls");
@@ -17,6 +20,13 @@ void Cls(){
         system("clear");
     #endif
 }
+void fflush_stdin(){
+  #ifdef _WIN32
+    fflush(stdin);
+  #else
+    __fpurge(stdin);
+  #endif
+}
 
 void welcome_message(){
     printf("><Welcome to the Student Union POS system><\n");//welcome messgae
@@ -37,11 +47,11 @@ int choices_selecter(char * Items[],int items,char * welcome_messages){
     }
     printf("%d. Exit\n",i+1);
     printf(">");
-  	fflush(stdin);
+  	fflush_stdin();
     scanf("%d",&choice);
     if(choice < 1 || choice > items+1){
         printf("Invalid choice...press any key to retry....\n");
-        fflush(stdin);
+        fflush_stdin();
         getchar();
     }
   }while(choice < 1 || choice > items+1);
@@ -53,12 +63,12 @@ char* prompt_item(char* prompt,bool empty_allowed){
     char* item = malloc(sizeof(char) * 100);
     do{
         printf("%s",prompt);
-        fflush(stdin);
+        fflush_stdin();
         scanf("%[^\n]",item);//input until /n
         if(!empty_allowed&&(item,"") == 0){//check if temp is not empty
             printf("Invalid input, try again?(y/n)\n");
             char temp[100];
-            fflush(stdin);
+            fflush_stdin();
             scanf("%[^\n]",temp);
             if(strcmp(temp,"n") == 0){
                 return NULL;
@@ -97,7 +107,6 @@ bool item_inputer(char * varname,INPUT_TYPE type,void * item,bool empty_allowed)
   return true;
 }
 
-//TODO: lister still useable
 void lister(void * db,struct Map* map, int row,char * lister_name,char * SortItems[],int NoSortItems,void (*page_printer)(void*,int,int,struct Map*) , struct Map* (*sorter)(void *,int),void * (*showitem)(void *,int)){
   int choice = -1;
     int page = 0;
@@ -131,7 +140,7 @@ void lister(void * db,struct Map* map, int row,char * lister_name,char * SortIte
     do{
         valid = true;
         printf("Please input your choice\n>");
-        fflush(stdin);
+        fflush_stdin();
         scanf("%d",&choice);
          if(choice <=NoSortItems && choice > 0){
             printf("sorting...\n");
@@ -152,7 +161,7 @@ void lister(void * db,struct Map* map, int row,char * lister_name,char * SortIte
             }
         }else if(choice == current_page_size+3){
             printf("Enter page size: ");
-            fflush(stdin);
+            fflush_stdin();
             scanf("%d", &page_size);
             total_pages = ceil((double)row / page_size);
         }else if(choice >= 9 && choice <= current_page_size){