status.i4.v = window_message_update_c(message_id.i2.v, message.i1a.r,

	This routine will update a single line message window that was
	created by an earlier call to window_message_create_c.  If the
	new message is longer than the existing message window, the window
	will be automatically resized to accommodate the new message.

	message_id	message window ID which was returned by an earlier
			call to window_message_create_c
	message		message to be displayed (must be null terminated)
	message_color	message color
			(constants are in 'cnsparam')
	pop_window	(WMNGR_POP_WINDOW -> pop message window to the front,
			 WMNGR_LEAVE_WINDOW -> leave window where it is)
			(Note: If the window is resized, it will be popped
			       to the front.)

	This function returns ACNET status values as follows:

	OK			success
	CBS_NO_SUCH		no such message window exists
	CBS_WINDOW_TOO_BIG	message window won't fit on the TV screen

	This function requires the following include files:

	cnsparam_h, cbslib_h, acnet_errors_h

	Related functions:

	window_message_create_c, window_message_delete_c

	C/C++ usage:

	static const char	overall_message[] = "This is the title!";
	static char	message[] = "This is the message inside the window!";
	short	message_id;
	int	status;
	int	top_row = TOP_ROW;
	int	left_column = LEFT_COLUMN;
	int	overall_color = OVERALL_COLOR;
	int	message_color = MESSAGE_COLOR;
	int	pop_window = WMNGR_LEAVE_WINDOW;

	status = window_message_create_c(top_row,left_column,overall_message,
	strcpy(message,"This is a new message to put in the window.");

	status = window_message_update_c(message_id,message,message_color,