var mess = new Array(
'<img src="http://cyrusfarivar.com/images/cyrus.ibook.jpg">',
'<img src="http://cyrusfarivar.com/images/cyrus.lecture.jpg">',
'<img src="http://cyrusfarivar.com/images/cyrus.pakol25.jpg">');
var max = mess.length;
var num = Math.floor((Math.random() * max));
document.writeln(mess[num]);