... nil But could someone please tell me how to save and restore a part of the canvas / screen. oMeta1:bMMoved:={|y,x,flags| hairCross(y,x, oMeta1)} Dim ScreenSave func hairCross(x,y, oMeta1) restore = ScreenSave ScreenSave = save part of the screen where you draw the new line oMeta1:line (y,0,y,500) ...