(maxgui) refresh canvas from another window

smattbac : I've already added the fellowing code to the
Draw_second_window()) into the 'case event_timertick' to redraw the canvas. but I've the similar problem.

			
				SetGraphics CanvasGraphics(Canvas1)
				Cls
				
				For Local i=0 To GadgetWidth (Canvas1) Step 32
					DrawLine i,0,i,GadgetHeight(Canvas1)
				Next
				
				SetColor 0,40,0
				For Local i=0 To GadgetHeight (Canvas1) Step 32
					DrawLine 0,i,GadgetWidth(Canvas1),i
				Next