Button event - something like on (hold)?

Hi,

I created a movieclip containing a button. I wrote an actionscript for this button. When it is clicked, a movieclip containing some thumbnails is scrolled to the left.

This is the code :


on (press) {
 lxposthumbs = thumbs_mc._x + thumbs_mc._width;
 lxposmask = thumbs_mask._x + thumbs_mask._width;
 if (lxposthumbs >= lxposmask)
 {
  pos = thumbs_mc._x - 75;
  _global.posit = _global.posit - 75;
  thumbs_mc.tween("_x",pos,0.35,"easeInOutQuad");
 }
}

What I would like is when I hold my mouse button down on the button, the thumbnails keep on scrolling. How do I do this? Something like an “on (hold)” is what I need.

Thnx in advance,

Grenouille