hitTest()

I was just playing around with the hitTest and was wondering if I could get some help on what I am doing wrong. What I am trying to do is when one moviclip rolls over the other I wanted the output to trace “hit”. Also what would I have to do to get this to work on a mouse click instead of a roll over.
startDrag("/Target", true, 0, 0, 400, 300);
setProperty("/VLine", _x, getProperty("/Target", _x));
setProperty("/HLine", _y, getProperty("/Target", _y));
ball._y +=2;
function collide(){
if (Target.hitTest(ball),true) {
trace(hit);
}
}

collide();

What I was trying to do is when on moviclip rolled over the other I wanted the output to trace “hit” Also how can I get it do the same trace on a mouse clik instead of a rollover.