Why do Buttons Work Through All Layers?

Greetings Forum!

I hope someone can help answer this ridiculous question that I can’t seem to fix.
I have a cascading/collapse flash menu.
There are about 7 layers, each one of them a different page that slides and covers the other layers.
My problem is, for some reason, all the buttons on the bottom layer (layer 1 for instance) can be clicked on even when the 6 other layers are ontop of it with their own links and buttons. How can I make it so all my buttons don’t shine through all the other layers. I can’t slide the layer away to get ride of the buttons because it is still partially viewed when the other layers are ontop of it. I can’t figure out why the buttons in layer one can be clicked in layer 2 when its on top of layer 1, or layer 3,4,5,6,7 when they are on top of layer 1-i assumed these layers would block out the buttons and links in the first layer(which is on the way bottom)

SO much appreciation for your help!