Simple RollOver fail to work before clicked once

[ddlam]

Hi, I have a simple rollover failed. Let say I have a movie clip "mv"

mv, frame 1, stop();
mv, frame 10, gotoAndPlay(2);

and I have and button "btn", I right click and press F9 and added the following codes

on (release) {
	btn.onRollOver = function() {
		mv.gotoAndPlay(2);
	};
}
on (release) {
	btn.onRollOut = function() {
		mv.gotoAndStop(1);
	};
}

As the result, I fail to see the rollover effect before I click the button once.
How to fix it?

Test file
http://www.2shared.com/file/89i1fT9q/rollover.html

Thanks for the attention.

[ddlam]

fixed
on (rollOver) {
mv.gotoAndPlay(2);
}
on (rollOut) {
mv.gotoAndStop(1);
}