//Calling technical stuff

    var canvas;

    var canvasContext;

    canvas = document.getElementById('gameCanvas');

    canvasContext = canvas.getContext('2d');

    // Initial values

    var ballX = (canvas.width-20)/2;

    var ballY = (canvas.height-20)/2;

    var yDirection = 2;

    var xDirection = 2;

    var PositionY;

    var drawEverythingCount = 0;

    // Constants

    var ballSize = 20;

    var panelHeight = 100;

    var panelWidth = 10;

    window.onload = function(){

    // Calls the main draw function and has the interval for repeating set to 10 ms

        setInterval(function() { 

          drawEverything(PositionY); 

        }, 10);

    }

    //Adds the event for mousemove to record the Y position of the mouse

    document.addEventListener("mousemove",function(event){

       PositionY = (event.clientY-(panelHeight/2));

    });

​

    function drawEverything(PositionY) {

    drawEverythingCount = drawEverythingCount + 1;

    // Draws the canvas, ball and panel

    canvasContext.fillStyle = 'black';

    canvasContext.fillRect(0,0, canvas.width, canvas.height);

    canvasContext.fillStyle = 'red';

    canvasContext.fillRect(ballX, ballY, ballSize, ballSize);

    canvasContext.fillStyle = 'green';

    canvasContext.fillRect(canvas.width-panelWidth, PositionY, panelWidth, panelHeight);

    // Resets the game if the ball goes out of the Right side of the canvas

    if (ballX > canvas.width) {

        alert('You scored:' + (xDirection - 2) + '!')

        ballX = (canvas.width - 20)/2;

        ballY = (canvas.height-20)/2;

        yDirection = 2;

        xDirection = 2; 

    } 

    // Checks to see if the ball is about to hit the left-hand wall

    if (ballX - xDirection < 0) {

      (xDirection = (xDirection*-1) + 1); ballX = 0;

    };

    // Checks to see whether or not the ball is about to go off of the canvas' y-axis and changes its 

    // direction

    if ((ballY+20) > canvas.height || ballY < 0) {

      if ((ballY+20) > canvas.height) {

          yDirection = -1;

      } else {

          yDirection = 1;

      }

    }

    // Checks to see if the ball is hitting the panel

    if ((ballX + xDirection) > (canvas.width - 10)) {

       var y;

       for (y = PositionY; y < (PositionY + 101);y++) {

         if(y == ballY) {

           xDirection = xDirection * -1;

           break;

         }

    }};

    // Movement of the ball

    ballY = ballY + yDirection;

    ballX = ballX + xDirection;

 }