AS2:: Scrolling a movie clip

Quick question:

I have this code:

on (release){
 animF_mc._x += -7;

that basically moves a movieclip left to create like a scrolling horizontal effect. BUT you have to constantly click the arrow button so I was wonder if there was a way to program it so that is I hold the mousedown on that button it keeps scrolling?

Thanks for any helpC:-)