	(SCALAR ADVERB)

	CCLICK is set by CLICK.  It corresponds to the value that
	the function CCUR would have returned at the crosshair 
	location when the user clicks a mouse button.

	For a plot made using SHOW, this is the channel number,
	for a plot made using PLOT, this is the x-axis value,
	and for a 2-d plot, it is the x-cell number.

