// JavaScript Document
ranimg = new Array(); 
ranimg[0]="top/swap01.jpg";
ranimg[1]="top/swap02.jpg"; 
ranimg[2]="top/swap03.jpg"; 
xx = Math.floor(ranimg.length*Math.random()); 
ranimg = ranimg[Math.floor(xx)]; 
document.write ('<style type="text/css"><!--#topimg {background-image: url("'+ ranimg +'");background-position: right;}--></style>');