.386 .model flat, stdcall option casemap:none include windows.inc include kernel32.inc include user32.inc includelib kernel32.lib includelib user32.lib .data MsgBoxCaption db "Simple MessageBox Program",0 MsgBoxText db "Hello World!",0 .code start: invoke MessageBox, NULL, addr MsgBoxText, addr MsgBoxCaption, MB_OK invoke ExitProcess,0 end start