myPix = new Array("images/layout/Top_change1.gif",
		"images/layout/Top_change2.gif",
		"images/layout/Top_change3.gif",
		"images/layout/Top_change4.gif")

 rnd.today=new Date();
 rnd.seed=rnd.today.getTime();

 function rnd() {
         rnd.seed = (rnd.seed*9301+49297) % 233280;
          return rnd.seed/(233280.0);
 };

 function rand(number) {
         return Math.ceil(rnd()*number);
 };