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;
} 

function update_sess()
{
xmlHttp=GetXmlHttpObject();
if (xmlHttp==null)
  {
  alert ("Your browser does not support AJAX!");
  return;
  } 
var url="/ajax_functions.php";
url=url+"?action=actualization";
url=url+"&rndid="+Math.random();
xmlHttp.onreadystatechange=sess_changed;
xmlHttp.open("POST",url,true);
xmlHttp.send(null);
}

function sess_changed() 
{
if (xmlHttp.readyState==1)
{
document.getElementById("sess_content").backgroundImage="none";
} else if (xmlHttp.readyState==4)
{
	if(xmlHttp.status == 200)
    {
		document.getElementById("sess_content").innerHTML = xmlHttp.responseText;
    }
    else
    {
        alert("Vaše prihlášení vypršelo!");
    }
//
}
}