MX 2004 Questions: How do I track the mouse cursor?

Hey all, first time posting on here, though I’ve read through the site quite a bit before.

Anyways, I’m working on a button navigation system that drops down to reveal sub menu buttons underneath, e.g. what you can see at http://www.kurani.com. I’ve succesfully managed to get the window to drop down, but I can’t attach code to the original button, as it is now hidden.

What I was thinking of doing is setting an actionscript to the frame itself, stating “If the mouse cursor leaves the confines of coordinates x,y: 0,0 to 180,75 , advance to the next frame.”

If this isn’t making any sense, please let me know, and I’ll try to reword it as well as I can.

Thanks again!