Animated button as3

Hi there

I have this animated button that I created from a tutorial, but am a little confused at to how I could set a hotspot for the button, the button is just a white outline square, no background image, so the button is not completely filled.

it only triggers when rollover line, am I making any sense.

is this the easiest way to create an animated button in as3, seems like there is alot of script???

I have attached fla example of button