Controling a movie in a button

[Groat]

I have a button with a movie clip in it. When i scroll over the button the first part of the movie plays. I want the second part of the movie to play when i scroll off the button. The movie clip is inside the button on the "over" state frame. i tried the following code and it didn't work.

Button name = ice_btn
Movie name = slider_mc

Code

ice_btn.addEventListener(MouseEvent.MOUSE_OUT, toIce);


function toIce(event:MouseEvent):void {
slider_mc.gotoAndPlay(6)
}