MovieClip Class

Hello,

I am new to action script 3.0 and i have been reading the tutorial about MovieClip classes on kirupa.com, and i learned a lot from it. Yet i have a question about doing a movieclip button class that does roll_over and roll_out function? I need that mostly because of understanding how the class work and if that Is anyhow possible and if it is, i would appreciate someone explaining to me an example of doing such thing.

More precisely, i need to know a process of tweening a button via class, so that on roll over it does tween i have entered via code and on roll_out other kind of a tween

Thanks, Dushan.