Scrolling text box in a rollover button?

Does anyone have a suggestion as to how i can make a text box scroll inside a button? I have a button that when you rollover opens a window with a text box, but as of now when i try to scroll the text the action does not register.

My AS is very simple to open the window:

on(rollOver){
gotoAndPlay(“bar in”);
}
on(rollOut){
gotoAndPlay(“bar out”);
}

Any suggestions would be great as i am not experienced in AS, Thanks…

I guess i have this code as a MC if that helps?