Need help with pong game

Im attemping to make my first game even tho it is a modified version of an example file in a book i bought.

My problem is the score right now. I already have a function that checks for collistions with the walls but i want to add some code to make the score go up one for the computer if the ball touches the left wall and go up 1 for the player if the ball touches the right wall. But my code wont work.

I have 2 dynamic text boxes 1 named YourScore for the players score and one named CompScore for the computers score. the code i added to set the initial scores for each player was

YourScore = 0; 
CompScore = 0;  

the code to raise the score by one for each player was put inside my checkforWalls function in the if statement.

this.YourScore += 1;
this.CompScore += 1;

Heres the source of my game and i am using flash MX 2004 Professional.

Thx in advance