Thank you both for your suggestions, however . . . . . .
1. From what I can make out "Pick top/bottom" only works on instances and I have lots of seperate objects to disable.
2. I have the objects on different layers but that method is not quite what I need to accomplish.
All of the objects still need to be clickable, just not when they are behind some thing else. I suppose what I need is some way of masking off the area when the menu is visible.
I hope this makes the problem a little clearer.
Thanks for your input anyway.