var banner=new Array();
banner[0]='<img border=0 src=/images/comm_header1.jpg alt="Header1"></a>';
banner[1]='<img border=0 src=/images/comm_header2.jpg alt="Header2"></a>';
banner[2]='<img border=0 src=/images/comm_header3.jpg alt="Header3"></a>';

var whichbanner=Math.floor(Math.random()*(banner.length));document.write(banner[whichbanner]);