Tell a movieclip within a movieclip to play

1

i am trying to make a movieclip within a movieclip play using event.target but cant seem to make it work…

var imc:MovieClip = new inputMC();
addChild(imc);

imc.sendButton.addEventListener(MouseEvent.MOUSE_OVER, mouseOverButton);

function mouseOverButton(event:MouseEvent):void
{
    //imc.sendButton.gotoAndPlay("theOne"); // <----- this one works
    event.target.gotoAndPlay("theOne"); // <----- doesn't do anything
    //event.target.sendButton.gotoAndPlay("theOne"); // <---- throws an error
}