AS3

## Adding a ball ##
# A ball get added and given an angle by the user clicking, drag and releasing:
# item.radians = Math.atan2(mouseUpY-mouseDownY, mouseUpX-mouseDownX);

# Then this code loops on each frame moving the ball

    # This part is how I'm checking if the ball has hit a wall
    # The left and right wall math seem to work fine
    if (item.x + (item.width / 2) >= stage.stageWidth || item.x - (item.width / 2) <= 0) {
        item.radians = Math.PI - item.radians;
    }


    if (item.y + (item.height / 2) >= stage.stageHeight) {
        // Hit bottom wall
    } else if (item.y - (item.height / 2) <= 0) {
        // hit top wall
    }


    // This then calculates how many pixels to move the ball
    var xVel:Number = Math.cos(item.radians) * item.speed;
    var yVel:Number = Math.sin(item.radians) * item.speed;

    item.x += xVel;
    item.y += yVel;