Detect Mouse Over?

Hey guys, I need a little help here.

I have a flash menu that, once the user rollover it, a drop-down menu will be shown.
Then I have made a button surrounding the menu - the Rollout button.
So when the user rollover on the Rollout button, the drop-down menu will close.

But when i upload it online onto an html page, the user somehow managed to “skip” the Rollout Button and the drop-down menu will remain. And this creates quite an annoyance as the menu will block most of the contents unless the user rollover and out of the menu again.

So i was wonder if it possible to create an if function that detect if the user’s mouse pointer is rolled over the menu. When it is not, the drop-down menu will close.

Is there a way to do this? I am using Flash 8.