添加用户购买的产品价格

Question

想要添加用户输入的产品价格以获得总账单，我现在将产品价格乘以数量以将价格保存在任何变量中，以便我可以添加它们并获得总账单

请告诉如何以变量的产品价格添加它们并找出总账单。 如何在此代码中使用添加指令？

先感谢您

INCLUDE LABMACRO.ASM
 .MODEL SMALL
 .STACK 100H
 .DATA

 M0 DW "********** WELCOME TO THE SUPER MARKET ********** $" 
 M1 DW " ENTER PRODUCT NAME  : $ "
 M2 DW " ENTER PRODUCT PRICE  : $ "
 M3 DW " ENTER PRODUCT QUANTITY  : $ "
 M4 DW " ADD MORE ITEMS <Y OR N>  : $ "
 M5 DW " TOTAL BILL  : $ "
 M6 DW " TOTAL COST OF PRODUCT  : $ "
 M7 DW "******************************************** $"


 VARN DB 10 , ? ,10 DUP(?)
 RES  DW ? 


.CODE 
MAIN PROC
MOV AX,@DATA
MOV DS,AX 

CURSOR_SET 00,0CH,10H 
DISPLAY M0
INPUT_CHAR CHAR
CMP AL,0DH
JE CLEAR_SCR
CLEAR_SCR:
CLEAR

AGAIN:
CLEAR
CURSOR_SET 01,0CH,10H
DISPLAY M7

CURSOR_SET 01,0DH,19H
DISPLAY M1
INPUT VARN

CALL MULTIPLY

AGAIN2:
CURSOR_SET 01,12H,19H
DISPLAY M4
INPUT_CHAR CHAR
CMP AL,'Y'
JE AGAIN
CMP AL,'N'
JE TOTAL 

TOTAL:
CURSOR_SET 01,15H,15H
DISPLAY M5
;CALL ADDITION
  
MOV AH,4CH
INT 21H

MAIN ENDP

MULTIPLY PROC 
CURSOR_SET 01,0EH,19H 
DISPLAY M2
mov cx,0
call InputNo
push dx
CURSOR_SET 01,0FH,19H
DISPLAY M3 
mov cx,0
call InputNo
pop bx
mov ax,dx
mul bx 
mov dx,ax
push dx
CURSOR_SET 01,10H,19H 
DISPLAY M6
mov cx,10000
pop dx
call View

CURSOR_SET 01,11H,10H 
DISPLAY M7 
jmp AGAIN2


      
  MULTIPLY ENDP 
         
         
  InputNo proc
             
  mov ah,0
  int 16h                                  
  mov dx,0  
  mov bx,1 
  cmp al,0dh                             
  je FormNo
  sub ax,30h 
  call ViewNo 
  mov ah,0 
  push ax  
  inc cx   
  jmp InputNo 
  
  FormNo:     
  pop ax  
  push dx      
  mul bx
  pop dx
  add dx,ax
  mov ax,bx       
  mov bx,10
  push dx
  mul bx
  pop dx
  mov bx,ax
  dec cx
  cmp cx,0
  jne FormNo
  ret   
      

  InputNo endp  

  View proc

   mov ax,dx
   mov dx,0
   div cx 
   call ViewNo
   mov bx,dx 
   mov dx,0
   mov ax,cx 
   mov cx,10
   div cx
   mov dx,bx 
   mov cx,ax
   cmp ax,0
   jne View
   ret
    
   view endp
       
   ViewNo proc          
       push ax 
       push dx 
       mov dx,ax 
       add dl,30h 
       mov ah,2
       int 21H
       pop dx  
       pop ax
       ret
       
    ViewNo endp 


    end main