Scale movieclips using loadmovie()

1

Hello,
I am loading some thumbnails (jpgs) into some movieclips using loadmovie. Easy enough. I want to scale the movieclip to increase the size of the thumbnail on rollover. The problem is when I use loadmovie and load the external JPG it sets the the JPGs default registration point to (0,0) and when I scale the thumbnail it scales from the top left corner. I would like it to scale from the center. This is the code I am using:

onClipEvent (load) {
var thumb = “thumbtest.jpg”;
loadMovie(thumb, thumb_loader);
thumb_loader._yscale = 70;
thumb_loader._xscale = 70;
}

on (rollOver) {
thumb_loader._yscale = 100;
thumb_loader._xscale = 100;
}

on (rollOut) {
thumb_loader._yscale = 70;
thumb_loader._xscale = 70;
}

Is there anyway to change the registration point so it scales from the center and not the top left?

thanks,
D