How to make scroller stop when menu is active

hi,

in my flash file i use a movieclip that scrolls images controlled by the mouse. there is a variable speed, and if it set to 0, the scroller is stopped.

so far it works fine.
but i also have a dropdown menu which overlaps the scroll area when it is unfolded. and so, if i want to navigate, the images keep quickly scrolling around, which is rather annoying.
the menu is inside a movie clip.

i think i’ll have to set the speed variable to 0 when the mouse rolls over the space that the menu occupies.

can you tell me if it works that way and how i have to actionscript that?

thanks a lot
jo