function insert_ad()
{
  var xmlHttp=GetXmlHttpObject();
  var url="";
  var insert="";

  if (xmlHttp==null)
  {
    alert ("Your browser needs to be updated.");
    return;
  }
  url="ads.php";
  xmlHttp.onreadystatechange=function()
  {
    if (xmlHttp.readyState==4 || xmlHttp.readyState=="complete")
    {
      document.getElementById("ads_right").innerHTML = xmlHttp.responseText;
    }
  }
  xmlHttp.open("GET",url,true);
  xmlHttp.send(null);
}

function GetXmlHttpObject()
{
  var xmlHttp=null;
  try
  {
    // Firefox, Opera 8.0+, Safari
    xmlHttp=new XMLHttpRequest();
  }
  catch (e)
  {
    // Internet Explorer
    try
    {
      xmlHttp=new ActiveXObject("Msxml2.XMLHTTP");
    }
    catch (e)
    {
      xmlHttp=new ActiveXObject("Microsoft.XMLHTTP");
    }
  }
  return xmlHttp;
}