function banner(graph,link){
	this.graph = graph;
	this.link = link;
}

var banners = new Array();
	banners[1] = new banner("banner02","http://www.towngasavenue.com/WND/wnd_e.html");
	//banners[2] = new banner("banner02","../../bannerDetailPage/kidsClass.pdf");
	//banners[1] = new banner("banner01","../../cafe/cafe.htm");
	//banners[4] = new banner("banner04","http://www.icare.com.hk/broadband/index.html");

var t = Math.round(Math.random() * 0) + 1

function showBanner(){
	var graph = banners[t].graph;
	var link = banners[t].link;
	var forBanner = "";
	forBanner += "<a href="+link+" target='_self'>";
	forBanner += "<img src='../../images/banner/" + graph + ".gif' border=0>";
	forBanner += "</a>"
	return forBanner;
}
<!-- // BannerAD

   var bannerAD=new Array();
   var bannerADlink=new Array();
   var adNum=0;

   bannerAD[0]="/images/banner/banner02.gif";
   //bannerADlink[0]="/cafe/cwb/dining/dining.aspx?id=1";
   bannerADlink[0]="/cookie/tgacookies_eng.html";   
   //bannerAD[0]="/images/banner/banner01.gif";
   //bannerADlink[0]="/cafe/cafe.htm";

   var preloadedimages=new Array();
   for (i=1;i<bannerAD.length;i++){
      preloadedimages[i]=new Image();
      preloadedimages[i].src=bannerAD[i];
   }

function setTransition(){
   if (document.all){
      bannerADrotator.filters.revealTrans.Transition=Math.floor(Math.random()*23);
      bannerADrotator.filters.revealTrans.apply();
   }
}

function playTransition(){
   if (document.all)
      bannerADrotator.filters.revealTrans.play()
}

function nextAd(){
   if(adNum<bannerAD.length-1)adNum++ ;
      else adNum=0;
   setTransition();
   document.images.bannerADrotator.src=bannerAD[adNum];
   playTransition();
   theTimer=setTimeout("nextAd()", 22900);
}

function jump2url(){
   jumpUrl=bannerADlink[adNum];
   jumpTarget='_blank';
   if (jumpUrl != ''){
      if (jumpTarget != '')window.open(jumpUrl,jumpTarget);
      else location.href=jumpUrl;
   }
}
function displayStatusMsg() { 
   status=bannerADlink[adNum];
   document.returnValue = true;
}