MASM FOR WINDOW 编译错误,求高人

   datarea segment
  string1 db 'move the cursor backward.'
  string2 db 'move the cursonr backward.'
  
  mess1 db 'Match$'           
  mess2 db 'No match!$'
  datarea ends
            
  prognam segment
  main proc far
  assume cs:prognam,ds:datarea,es:datarea
  start:
  ;set up  stack for return
          push ds
          sub ax,ax
          push ax
    mov ax,datarea
    mov ds,ax
    mov es,ax
    ;main part of program goes here
       lea si,string1
       lea di,string2
       cld
       mov cx,25
       repz cmpsb
       jz match
       lea dx,mess2
       jmp short disp
    match:
       lea dx,mess1
    disp:
        mov ah,09
        int 21h
        ret;return to DOS
        main endp
        prognam ends
        end start



错误为 A2006 ,start 未定义


[ 本帖最后由 术鱼 于 2011-11-27 21:52 编辑 ]