Button Animation

I created a little news viewer, that when you roll over a button it plays an animation. The problem I am having is:

if the mouse moves over the button (the animation starts)
– then if the mouse moves off the button

  • and then back over the button
    before the animation is over the animation snaps back to the first frame.

Is there a way to tell flash to ignore this “Double rollover” until the animation is finished? I’m sure this is cake to someone out there but I just cannot figure it out. Thanks!