b1up=new Image(107,36);
b1up.src="images/b1a.jpg";
b1down=new Image(107,36);
b1down.src="images/b1.jpg";

b2up=new Image(72,36);
b2up.src="images/b2a.jpg";
b2down=new Image(72,36);
b2down.src="images/b2.jpg";

b3up=new Image(63,36);
b3up.src="images/b3a.jpg";
b3down=new Image(63,36);
b3down.src="images/b3.jpg";

b4up=new Image(72,36);
b4up.src="images/b4a.jpg";
b4down=new Image(72,36);
b4down.src="images/b4.jpg";