In this tutorial, we're going to learn how to create basic AS3 collision detection using the AS3 hitTestObject() method of the MovieClip class. Collision detection refers to the process of checking whether 2 or more objects are hitting each other - if

function mouseUpHandler(evt:MouseEvent):void { var obj = evt.target; // obj.dropTarget will give us the reference to the shape of // the object over which we dropped the circle.

I far from recommend that - but I am extending the code given in the question. Perhaps, in his case he has only 1 bullet (I don't know because he hasn't outlined that) - so I need to go on the assumption he knows his project and has chosen to add