status.i4.v = window_read_background_size(num_rows.i4.r,

	This routine allows the application programmer to read the size
	of the background (or root) window.

	num_rows	returned number of rows  (A value of NULL may
			be passed if the number of rows is not needed.)
	num_columns	returned number of columns  (A value of NULL may
			be passed if the number of columns is not needed.)

	This function returns ACNET status values as follows:

	OK			success
	CBS_MEMFAIL		dynamic memory allocation failure

	This function requires the following include files:

	cnsparam_h, cbslib_h, acnet_errors_h

	Related functions:

	window_set_background_size(_c), window_size(_c), intro_tv_windows

	C/C++ usage:

	int	status;
	int	num_rows;
	int	num_columns;

	status = window_read_background_size(&num_rows,&num_columns);