Release after drag

Hi,
I’ve got a drag/drop problem.
I’ve included the source and the marked the layers of interest with *** and named as follows:

layers
********** sleepsystemdrag (symbol: sleepsystemdrag)
->******** sleep system (symbol: sleepsystembtn)
************* btn (symbol: btnOverlay)

the [symbol: sleepsystembtn] has the following actionscript attached;

on (press) {
Mouse.hide();
_parent.sleepsystemdrag._alpha = 30;
startDrag("_parent.sleepsystemdrag");
}
on (release) {
_parent.sleepsystemdrag._alpha = 0;
stopDrag();
_parent.sleepsystemdrag._x = 95;
_parent.sleepsystemdrag._y = 188;
Mouse.show();
}

a btn was used as the target area is quite specific. My problem is that the on(release) code is never activated when the [symbol: sleepsystemdrag] is dragged **outside **the [symbol: sleepsystembtn] target area. Is it possible to attach an on(release) method to the mouse in general, and one that isnt only activated within the btn’s target area?

hope i explained this with enough clarity,
thanks,
scarab

**the source
**http://www.nikken.co.uk/problem/drag_problem1.fla