button animations...

[c_iannacone]

hey, i was wondering how exactly i would get a raster animation inside of a button on the rollover...ive seen it done on a site, cant remember which one, but when you rolled over the button, an amazing animation of streaking plasma or the like flashed from left to right inside of the button...im thinking its some type of imported gif...does anyone know of any ways to either recreate this effect or where to find some small effects movies to mask inside of the button? thanks!

[FlashKid105]

Can you post an example of this?

Also, one way to have an animation inside a button would be to import that animation into Flash as an MC and put that MC inside the Over state of a button