//PreLoad Images
	a1 = new Image();
	a1.src = "images/a1.gif";
	a2 = new Image();
	a2.src = "images/a2.gif";
	b1 = new Image();
	b1.src = "images/b1.gif";
	b2 = new Image();
	b2.src = "images/b2.gif";
	c1 = new Image();
	c1.src = "images/c1.gif";
	c2 = new Image();
	c2.src = "images/c2.gif";
	d1 = new Image();
	d1.src = "images/d1.gif";
	d2 = new Image();
	d2.src = "images/d2.gif";