var xmlHttp

function ajaxkeepalive(str)
{
   xmlHttp=GetXmlHttpObject()
   if (xmlHttp==null)
   {
      alert ("Browser does not support HTTP Request")
      return
   }
   var url=page_to_request
   url=url+"?q="+str
   url=url+"&sid="+Math.random()
   xmlHttp.onreadystatechange=stateChanged
   xmlHttp.open("GET",url,true)
   xmlHttp.send(null)
}

function stateChanged()
{
   if (xmlHttp.readyState==4 || xmlHttp.readyState=="complete")
   {
      document.getElementById(response_id).innerHTML=xmlHttp.responseText
   }
}

function GetXmlHttpObject()
{
   var objXMLHttp=null
   if (window.XMLHttpRequest)
   {
      objXMLHttp=new XMLHttpRequest()
   }
   else if (window.ActiveXObject)
   {
      objXMLHttp=new ActiveXObject("Microsoft.XMLHTTP")
   }
   return objXMLHttp
}