pro cancel,event

;Author: Rick Pernak, NASA Goddard Space Flight Center

;cancel button in ff_gui: destroys gui and frees pointers

widget_control,event.top,get_uvalue=datptr
dat = *datptr

*dat.vis_un = 0
*dat.vis_edit = 0
*dat.vis_con = 0
*dat.visfit = 0
*dat.sigma = 0
*dat.visin = 0

widget_control,event.top,/destroy

end