function OnCheckAvailability()
{
   //alert("Are you sure want to close the window?");
   var objReq=null; 
   if(window.XMLHttpRequest)
   {
       objReq=new XMLHttpRequest();
   }
   else if(window.ActiveXObject)
   {
        try
        {
            objReq=new ActiveXObject("Microsoft.XMLHTTP");
        }
        catch(e)
        {
            objReq=new ActiveXObject("Msxml2.XMLHTTP");
        }
   } 
   
	objReq.open("GET", "unolad.aspx", true);
	//oRequest.onreadystatechange = UpdateCheckAvailability;
    
	//oRequest.setRequestHeader("Content-Type", "application/x-www-form-urlencoded");
	
	objReq.send(null);
}