function getAdUrl(){
var urls = initializeUrls();
var rand = Math.floor(Math.random()*urls.length);
var adUrl = urls[rand];
	
return adUrl;

}

function initializeUrls(){

var url_array = new Array();

url_array[0] = "http://referer.us/yttrk.com/?a=149707&c=13794&s1=";
//60sec
url_array[1] = "http://referer.us/yttrk.com/?a=149707&c=12855&s1=";
//HQI
url_array[2] = "http://referer.us/yttrk.com/?a=149707&c=12883&s1=";
//QN-AI
url_array[3] = "http://referer.us/yttrk.com/?a=149707&c=12894&s1=";
//s500

return url_array;

}