var ie=document.all&&navigator.userAgent.indexOf("Opera")==-1
var dom=document.getElementById&&navigator.userAgent.indexOf("Opera")==-1
var iframeprops='width="480" height="60" marginwidth="0" marginheight="0" hspace="0" vspace="0" frameborder="0" scrolling="no"'

//Specify random URLs to display inside iframe
var randomcontent=new Array()
randomcontent[0]="ads/ion.html"
randomcontent[1]="ads/usoncology.html"
randomcontent[2]="ads/treanda.html"
randomcontent[3]="ads/impac.html"
randomcontent[4]="ads/zolinza.html"
randomcontent[5]="ads/varian.html"
randomcontent[6]="ads/nccn.html"
randomcontent[7]="ads/iKnowMed.html"

if (ie||dom)
document.write('<iframe id="banner" src="" '+iframeprops+'></iframe>')

function random_iframe(){
if (ie||dom){
var iframeobj=document.getElementById? document.getElementById("banner") : document.all.banner
iframeobj.src=randomcontent[Math.floor(Math.random()*randomcontent.length)]
}
}

window.onload=random_iframe