title: How to build a MS-DOS program with MASM32 in XP SP3
body: <p>I'm new to assembly.
  I'm using MASM32 on WIN XP SP3.
  Whenever I try to assemble the code I get a warning.</p>
  
  <pre><code>.model small
  .stack 100h
  .code
  main proc
  mov ah,1
  int 21h
  mov bl,al
  mov ah,2
  mov dl,bl
  int 21h
  mov ah,4ch
  int 21h
  main endp
  end main
  </code></pre>
  
  <p>After assembling ASM file</p>
  
  <blockquote>
    <p>C:\masm32\coa.asm(14) : warning A4023: with /coff switch, leading underscore required for start address : main<br>
     Volume in drive C has no label.<br>
     Volume Serial Number is A868-C4EC<br>
     ...</p>
  </blockquote>
  
  <p>please tell what to do :( 
  thanks</p>