CS3 AS2.0 - Collision problem

Hi Flashkit community,

I have a small problem I would like your help on today. I know I should be close to the answer, but spending hours trying to figure it out, my mind just crashed... so I'm asking for any help at all.

Code:

---

this.onEnterFrame = function(){
        moveUpArrow();
        moveDownArrow();
        moveLeftArrow();
        moveRightArrow();
        if(_root.rootClip.hitBox_mc.hitTest(_root.upArrowMc)) {
                _root.rootClip.score ++;
        }
}

var arrowSpeed = 2.5;
var arrowReady = true;
var arrowDelay = 130;
var arrowArray = [];
var arrowCount = 0;

function createUpArrow(){
        var upArrowMc = _root.rootClip.attachMovie("Up", "Up" + arrowCount, 1000 + arrowCount);
        arrowCount ++;
        upArrowMc._x = 500;
        upArrowMc._y = 768
        arrowArray.push(upArrowMc);
}
function moveUpArrow(){
        if(arrowReady && Key.isDown(Key.UP)){
                arrowReady = false;
                currentTime = getTimer();
                createUpArrow();
                _root.rootClip.score += random(100) +1;
        } else{
                if(currentTime + arrowDelay <= getTimer()){
                        arrowReady = true;
                }
        }
        for (var i = 0; i<arrowArray.length; i++){
                arrowArray[i]._y -= arrowSpeed;
        }
}

---

This is what I got right now, I left out the code for Down, Left and Right functions, since they are pretty much the same.
THE PROBLEM I have is the collision area... for some reason, the collision doesn't detect when there is an array involved with an attached MC. I know there has to be a way to detect this collision, (ie. games that have shooting bullets, damaging enemies, etc)

So if anyone can modify my code, or even just point me into the right direction, I would be very grateful.

Thanks in advance!

Sorry for the double post everyone, but I realized, i can achieve what i need with a simple distance formula.

So if anyone can help me. I don't know where to put this statement:

if("arrow_object"._y <= 120){
_root.rootClip.score += random(100) +1;
}

I've tried this statement in many places, but i must have screwed up somewhere, it doesn't work correctly. The "arrow_object" is what ever the object should be. I have no clue why it doesn't work. I tried upArrowMc, but that didn't work.

Anyway, any help would be great
Thanks