/* background images */
var img1 = new Image();
img1.src = "images/bg_img.jpg";

var img2 = new Image();
img2.src = "images/bg_img_1.jpg";

var img3 = new Image();
img3.src = "images/bg_img_2.jpg";

var img4 = new Image();
img4.src = "images/bg_img_3.jpg";