Button "OVER" state

hi
is there a way to make the over state of a button with action script? what i want to do is to load a movieclip with an image wich has an invisible button behind it,well i want to put a red rectangle around the movieclip when we pass with mouse over it, how can i do this?

You put your red rectangle where you want it to be, set it as _visible=0, and then when you rollOver your button, you do theRectangle._visible=1;

pom :cowboy: