Trying to make scoring for my game work but having trouble

Hiya guys

I’m trying to add a scoring element to the game I have been teaching a bunch of kids to make over the last few weeks. I’ve created a variable called score which is set to 0 and a second variable that is equal to score. The idea is that when the player hits a red block it gives them 10 points. I can make the score increase by 10 by then it stops there and doesn’t increase when you hit other blocks. I’m pretty sure I’m missing something that i logically need but I can’t quite see it. Any help would be greatly appreciated.

//add the event listener to listen when a key is pressedstage.addEventListener(KeyboardEvent.KEY_DOWN, CharacterMove);


//variables added for the score
var score:Number=0+scoreCount;
var scoreCount=0;


//add the function to tell the object which direction to move and how far
function CharacterMove(event:KeyboardEvent):void {
	switch (event.keyCode) {
	case Keyboard.UP :
	MainCharacter.y-=10;
	break;
	case Keyboard.DOWN :
	MainCharacter.y+=10;
	break;
	}
//controls the boundaries of the stage	
	if (MainCharacter.y<0) {        
       MainCharacter.y=0;    
   	}    
   	else if (MainCharacter.y > 400-73) {
       MainCharacter.y=400-73;  //height of the stage minus the hieght of the character
   	}		
}


//add the event listener to listen when a collision is detected
MainCharacter.addEventListener(Event.ENTER_FRAME, checkCollision);


//add the function to check if the objects collide
function checkCollision(event:Event) {
	
	//test the mainCharacter to see if it overlaps a block
	if  (MainCharacter.hitTestObject(BlueBlock)) {
		gotoAndPlay("end");
	}
	if  (MainCharacter.hitTestObject(BlueBlock2)) {
		gotoAndPlay("end");
	}
	if  (MainCharacter.hitTestObject(BlueBlock3)) {
		gotoAndPlay("end");
	}
	if  (MainCharacter.hitTestObject(BlueBlock4)) {
		gotoAndPlay("end");
	}
	if  (MainCharacter.hitTestObject(BlueBlock5)) {
		gotoAndPlay("end");
	}
	if  (MainCharacter.hitTestObject(BlueBlock6)) {
		gotoAndPlay("end");
	}
	if  (MainCharacter.hitTestObject(BlueBlock7)) {
		gotoAndPlay("end");
	}
	if  (MainCharacter.hitTestObject(BlueBlock8)) {
		gotoAndPlay("end");
	}
	if  (MainCharacter.hitTestObject(RedBlock1)) {
		messageText.text = score +(scoreCount+10);
	}
	if  (MainCharacter.hitTestObject(RedBlock2)) {
		messageText.text = score +(scoreCount+10);
	}
}

Cheers guys. I know the code is not particularly well written and could be done much more professionally but the idea is that I teach the kids a new thing to add each week and this is the way it works.