Need help creating a score system...

Hey guys,

I have followed an online tutorial, I now need a score system that will make it so when all of the items are dropped onto the right location the user can click a button and move onto the next frame, I've tried several things but none of them have worked, so I thought you guys might be able to help me...

Here is my code:

stop();
//http://passyworldofict.blogspot.co.uk/
var objectoriginalX:Number; 
var objectoriginalY:Number; 
germany_mc.buttonMode = true; 
germany_mc.addEventListener(MouseEvent.MOUSE_DOWN, pickupObject); 
germany_mc.addEventListener(MouseEvent.MOUSE_UP, dropObject); 
france_mc.buttonMode = true; 
france_mc.addEventListener(MouseEvent.MOUSE_DOWN, pickupObject); 
france_mc.addEventListener(MouseEvent.MOUSE_UP, dropObject); 
italy_mc.buttonMode = true; 
italy_mc.addEventListener(MouseEvent.MOUSE_DOWN, pickupObject); 
italy_mc.addEventListener(MouseEvent.MOUSE_UP, dropObject); 
uk_mc.buttonMode = true; 
uk_mc.addEventListener(MouseEvent.MOUSE_DOWN, pickupObject); 
uk_mc.addEventListener(MouseEvent.MOUSE_UP, dropObject);
function pickupObject(event:MouseEvent):void { 
event.target.startDrag(true); 
event.target.parent.addChild(event.target); 
objectoriginalX = event.target.x; 
objectoriginalY = event.target.y; 
} 
function dropObject(event:MouseEvent):void { 
event.target.stopDrag(); 
var matchingTargetName:String = "target" + event.target.name; 
var matchingTarget:DisplayObject = getChildByName(matchingTargetName); 
if (event.target.dropTarget != null && event.target.dropTarget.parent == 
matchingTarget){ 
event.target.removeEventListener(MouseEvent.MOUSE_DOWN, pickupObject); 
event.target.removeEventListener(MouseEvent.MOUSE_UP, dropObject); 
event.target.buttonMode = false; 
event.target.x = matchingTarget.x; 
event.target.y = matchingTarget.y; 
} else { 
event.target.x = objectoriginalX; 
event.target.y = objectoriginalY; 
} 
}

Any help is much appreciated.