var mess = new Array('<img src="images/homepage_center2.jpg">','<img src="images/homepage_center3.jpg">','<img src="images/homepage_center6.jpg">','<img src="images/homepage_center7.jpg">','<img src="images/homepage_center8.jpg">');
var max = mess.length;
var num = Math.floor((Math.random() * max));
document.writeln(mess[num]);