NAME
	ModeNotAvailable -- check to see if a DisplayID isn't available. (V36)

   SYNOPSIS
	error =  ModeNotAvailable( modeID )
	d0		           d0

	 ULONG	ModeNotAvailable(  ULONG);

   FUNCTION
	returns an error code, indicating why this modeID is not available, 
	or NULL if there is no reason known why this mode should not be there.

   INPUTS
	modeID -- a 32 bit DisplayInfoRecord identifier.

   RESULT
	error -- a general indication of why this modeID is not available,
		 or NULL if there is no reason why it shouldn't be available.

   NOTE
	 ULONG return values from this function are a proper superset of the
	DisplayInfo.NotAvailable field (defined in  sc:include/graphics/displayinfo.h).

   BUGS

   SEE ALSO
	 sc:include/graphics/displayinfo.h,  GetVPModeID()