MouseOver sound problem

programming flash
1

I want my buttons to play a sound when the mouse rollover but I keep getting Error 1061 and i have no idea how to solve it.
Do i need to import anything or im doing this wrong? ( my sound in the library is properly linked )

var buttons:Array = [ one_btn, two_btn, three_btn ];
for (var i:int = 0; i<buttons.length; i++){
    buttons*.addEventListener(MouseEvent.MOUSE_OVER, mSound);
}

var soundOver:Sound = new Sound();
soundOver.attachSound("Arcade.mp3");

function mSound(event:MouseEvent):void{
    soundOver.start();
}