Communicating between levels

Hi there…
I want to load in a new _level *.swf. This new level contains a button which will have a stop command, which I want to work with an MC in the _root *.swf level.

_level1

loadMovieNum("level2.swf",2);

_level2

stop_mc.onRelease = function()
{
_parent.box_mc.stop();
}

This is how I thought it would work. I am wrong. Can anyone shed light to this??:stare: