graphics.clear();
graphics.lineStyle(3,0x0000FF,1);
graphics.moveTo(0,315);
graphics.lineTo(stage.stageWidth, 315);
graphics.lineStyle(1,0xFF0000, 1);

var top = false;
var ymov = 0;
var bouancy = -2;
var gravity = 4;
var mass = 1;
var yAccel = (bouancy + gravity) / mass;

ball.buttonMode = true;

stage.addEventListener(Event.ENTER_FRAME, moveBall);
ball.addEventListener(MouseEvent.MOUSE_DOWN, pickUpBall);
ball.addEventListener(MouseEvent.MOUSE_UP, dropBall);

function moveBall(event:Event):void
{
	//add yAccel to ymov
	ymov += yAccel;

	//move the ball by changing the y property using the ymov variable
	ball.y += ymov;
	
	if(ymov > 0 && !top)
	{
		//draw a line using moveTo and lineTo from the left edge of the stage to the right edge of the stage
		// using ball.y makes the line height = middle of ball
		graphics.lineStyle(1, 0xFF00FF);
		graphics.moveTo(0,ball.y);
		graphics.lineTo(stage.stageWidth, ball.y);
		
		top = true;
	}
	
	if(ymov <0  && top)
	{
		top = false;
	}
	
	if(ball.y >= 300)
	{
		//set ball to an appropriate height, the blue line
		ball.y = 300;

		//reverse the direction of the ball, use the ymov variable
		ymov *= -1;

		//add .1 to the bouancy variable
		bouancy += .1;

	}
	
	if(bouancy >= 0)
	{
		stage.removeEventListener(Event.ENTER_FRAME, moveBall);
	}	
}

function pickUpBall(event:MouseEvent):void
{
	event.currentTarget.startDrag();
}

function dropBall(event:MouseEvent):void
{
	stopDrag();
	bouancy = -2;
	stage.addEventListener(Event.ENTER_FRAME, moveBall);
	graphics.clear();
	graphics.lineStyle(3,0x0000FF,1);
	graphics.moveTo(0,315);	
	graphics.lineTo(stage.stageWidth, 315);
	graphics.lineStyle(1,0xFF0000, 1);	
}