When you disable a menu item, the menu text changes to gray, and the menu macro is made unavailable. To disable a menu item, use the following macro:
DisableItem("item_id")
For example, to disable the Options menu item, you use the following macro:
DisableItem("mnu_options")
The EnableItem macro activates a disabled macro. For example, to activate the Copy Bitmap menu item, you use the following macro:
EnableItem("mnu_copybmp")