var img = new Array ();

img[0] = "top12.jpg";
img[1] = "top21.jpg";
img[2] = "top23.jpg";
img[3] = "top25.jpg";
img[4] = "top42.jpg";
img[5] = "top47.jpg";
img[6] = "top49.jpg";
img[7] = "top54.jpg";

var i = Math.floor((img.length)*Math.random())