DEF Win:WINDOW
DEF Close:CHAR

DEF ScreenSizeX,ScreenSizeY:UINT
DEF L,T,ClientWidth,ClientHeight:INT

GETSCREENSIZE(ScreenSizeX,ScreenSizeY)

OPENWINDOW Win,0,0,ScreenSizeX,ScreenSizeY,@MAXBOX|@MINBOX|@SIZE|@MAXIMIZED,NULL,"Get client area",&MainHandler

'Left and top are always zero for this function.
GETCLIENTSIZE (Win,L,T,ClientWidth,ClientHeight)

PRINT Win,"Maximum drawing area values: width is"+STR$(ClientWidth)+" and height is"+STR$(ClientHeight)+"."

WAITUNTIL Close=1

CLOSEWINDOW WIN

END

SUB MainHandler

	SELECT @MESSAGE

	CASE @IDCLOSEWINDOW

	Close=1

	ENDSELECT

RETURN
ENDSUB

Output: Maximum drawing area values: width is 1280 and height is 749.