 * velocity;

    // Set colour of element
    var color = colors[Math.floor(PerfTestHelper.random() * colors.length)];

    function draw(timeDelta)
    {
        var timeDeltaSeconds = timeDelta / 1000;
        var testX = x + (dx * timeDeltaSeconds);
        var testY = y + (dy * timeDeltaSeconds);

        if (testX < 0 || testX > stageWidth) {
            dx = -dx;
            x += dx;
        } else {
            x = testX;
        }
        if (testY < 0 || testY > stageHeight) {
            dy = -dy