Looping expanding web banner

Hi there,

I’ve been asked to produce an expanding web banner for a client. I have produced static banners before but never expanding.

Basically I have a simple button that expands from 468x60 to 468x240, but I need a continuous looping animation that will cover all states of the button.

Please take a look at http://www.propellergraphics.co.uk/banner to see what I mean.

I thought this would be pretty simple but I have since realised I have never built a button that is continuously animating!

Any help would be greatly appreciated, also if anyone has any knowledge on any extra info such as javascript functions which may need to be applied to have the banner expand the div on the HTMl page.

Thanks for any help,

Bruce