;+
; This procedure toggles a flag to draw a horizontal line on the plot
; at the zero level
;
; @examples
;   zline
;
; @version $Id: zline.pro,v 1.2 2005/01/20 20:35:14 bgarwood Exp $
;-

pro zline
	common gbtplot_common,mystate,xarray
	mystate.zline = 1-mystate.zline
	show,/reshow
end