Is there a way to determine whether or not a previously created canvas is still present. I have an application with several canvases open at once. Depending on the actions of the user, some may be freed at any time. I know I can check for various gadget events to keep track of windows/gadgets, but is there a way to see if a canvas is still in memory before I use a command like 'mousex(canvas)' - which will generate an error if that canvas no longer exists. Thanks.