b1 = new Image();
b1.src = "images/b1_on.jpg";
b2 = new Image();
b2.src = "images/b2_on.jpg";
b3 = new Image();
b3.src = "images/b3_on.jpg";
b4 = new Image();
b4.src = "images/b4_on.jpg";
b5 = new Image();
b5.src = "images/b5_on.jpg";
b6 = new Image();
b6.src = "images/b6_on.jpg";
b7 = new Image();
b7.src = "images/b7_on.jpg";
b8 = new Image();
b8.src = "images/b8_on.jpg";
b9 = new Image();
b9.src = "images/b9_on.jpg";
b10 = new Image();
b10.src = "images/b10_on.jpg";
b11 = new Image();
b11.src = "images/b11_on.jpg";
b12 = new Image();
b12.src = "images/b12_on.jpg";
b13 = new Image();
b13.src = "images/b13_on.jpg";