Just to add something to that for Dan, If the string gadget that you wish to
activate is in a window which you are opening JUST BEFORE ActivateGadget() is
called, ActivateGadget() will fail. Since that Amiga is multi-tasking,
OpenWindow() may return BEFORE the window is actually added to the system list.
If this is the case when ActivateGadget() is called, AG will think the window
doesn't exist yet and it will fail. The solution is to place a small delay in
between OpenWindow() and ActivateGadget(). eg. Delay(10)