include 'win32a.inc'

format PE GUI 4.0
entry start

  start:
        invoke  GetModuleHandle,0
        invoke  DialogBoxParam,eax,37,HWND_DESKTOP,DialogProc,0
        invoke  ExitProcess,0

proc DialogProc hwnddlg,msg,wparam,lparam
        push    ebx esi edi
        cmp     [msg],WM_CLOSE
        je      wmclose
        xor     eax, eax
        jmp     finish
  wmclose:
        invoke  EndDialog,[hwnddlg],0
  processed:
        mov     eax,1
  finish:
        pop     edi esi ebx
        ret
endp

section '.idata' import data readable writeable

  library kernel,'KERNEL32.DLL',\
          user,'USER32.DLL'

  import kernel,\
         GetModuleHandle,'GetModuleHandleA',\
         ExitProcess,'ExitProcess'

  import user,\
         DialogBoxParam,'DialogBoxParamA',\
         EndDialog,'EndDialog'

section '.rsrc' resource data readable

  directory RT_DIALOG,dialogs

  resource dialogs,\
           37,LANG_ENGLISH+SUBLANG_DEFAULT,demonstration

  dialog demonstration,'Create message box',0,0,679,457,WS_CAPTION+WS_SYSMENU

  enddialog    

Every dialog box template contains measurements that specify the position, width, and height of the dialog box and the controls it contains. These measurements are device independent, so an application can use a single template to create the same dialog box for all types of display devices. This ensures that a dialog box will have the same proportions and appearance on all screens despite differing resolutions and aspect ratios between screens.

Dialog box measurements are given in dialog base units. One horizontal unit is equal to one-fourth of the average character width for the system font. One vertical unit is equal to one-eighth of the average character height for the system font. An application can retrieve the number of pixels per base unit for the current display by using the GetDialogBaseUnits function. An application can convert measurements from dialog base units to pixels by using the MapDialogRect function.