Easing Rollover Effect for menu

Hi. I’m not all that great with actionscript, so I’ll just ask all ya’ kirupians.

For my menu, I have a white image that I want to ease into the button on rollover, so it goes from the bottom, where it’s not seen, and it eases to fill the button, then the same ease out when the mouse is off of the button. I have no idea how to code this, and I don’t want to make movie clips, to keep the file size down.

Help would be greatly appreciated. Thanks.

GBP