Assembly errors on visual studio

INCLUDE Irvine32.inc

.386 .model flat, stdcall .stack 4096 ExitProcess proto, dwExitCode:dword

.model small

.stack 100h

.data

prompt1 db 13, 10, 'First number','$'

prompt2 db 13, 10, 'Second number','$'

prompt3 db 13, 10, 'Third number','$'

prompt4 db 13, 10, 'Fourth number','$'

result db 13, 10, 'input number','$'

;Variables

num1 dw ?

num2 dw ?

num3 dw ?

num4 dw ?

sum dw ?

.code

main proc

mov ax,@data ;get data segment address

mov ds,ax ;initialize ds

;Display prompt

mov ah,9 ;print string function

mov dx,offset prompt1 ;dsdx points to string

int 21h

; Numbers from the user

mov ah,1 ;input function

int 21h

xor ah,ah

mov num1, ax

mov ah,9

lea dx, prompt2 ;print prompt

int 21h

mov ah,2 ;input second function

int 21h

xor ah,ah

mov num2, ax

mov ah,9 ;print string function

mov dx,offset prompt3 ;ds:dx points to string

int 21h

mov ah,3 ;input function

int 21h

xor ah,ah

mov num3, ax

mov ah,9

lea dx, prompt4 ;print prompt

int 21h

mov ah,4 ;input fourth function

int 21h

xor ah,ah

mov num4, ax

;Addition

sub num1,'0'

sub num2,'0'

sub num3,'0'

sub num4,'0'

mov ax,num1 ;move num1 into ax

add ax,num2 ;add first and second numbers together

sub ax,num3

add ax,num4

mov sum,ax ;move the total sum of numbers in sum

add sum,'0'

;Print Sum

mov ah,9

lea dx, result ; print result

int 21h

mov ah,2

mov dl,bl

int 21h

mov dl,'+' ;display + sign

int 21h

mov dl,bh

int 21h

mov dl,'=' ;display = sign

int 21h

mov dl,bh

int 21h

mov ah,4ch

int 21h

invoke ExitProcess,0

main endp

end main

Properties 100 % Error List 4Errors | 2 warnings (D 0 Messages | Build-IntelliSense Search Error List Entire Solution Code A4011 A4011 Description Project MASM MASM File main.asm main.asm main.asm main.asm main.asm Line Suppression State multiple.MODEL directives found : .MODEL ignored multiple .MODEL directives found : .MODEL ignored instruction ope instruction operands must be the same size rands must be the same size A2022 A2004 48 80 40 MASM symbol type conflict The command "ml.exe/cologo/Sg/Zi/Fo"Debugimain.obj/ MSB3721 FI"MASM.Ist" /I"C:lirvine" /W3 /errorReport:prompt /Tamain.asm" exited MASM masm.targets 69 with code 1 Properties 100 % Error List 4Errors | 2 warnings (D 0 Messages | Build-IntelliSense Search Error List Entire Solution Code A4011 A4011 Description Project MASM MASM File main.asm main.asm main.asm main.asm main.asm Line Suppression State multiple.MODEL directives found : .MODEL ignored multiple .MODEL directives found : .MODEL ignored instruction ope instruction operands must be the same size rands must be the same size A2022 A2004 48 80 40 MASM symbol type conflict The command "ml.exe/cologo/Sg/Zi/Fo"Debugimain.obj/ MSB3721 FI"MASM.Ist" /I"C:lirvine" /W3 /errorReport:prompt /Tamain.asm" exited MASM masm.targets 69 with code 1