var xmlhttp=false;
if (!xmlhttp && typeof XMLHttpRequest!='undefined') {
try
  {  // Firefox, Opera 8.0+, Safari 
   xmlhttp=new XMLHttpRequest();  
   }
catch (e)
  { 
   // Internet Explorer  
   try
    {   
     xmlhttp=new ActiveXObject("Msxml2.XMLHTTP");    
    }
  catch(e)
    {   
     try
      {    
        xmlhttp=new ActiveXObject("Microsoft.XMLHTTP");     
       }
    catch(e)
      {     
     alert("Your browser does not support AJAX!");      
      xmlhttp=false;   
      }   
 
  } 
}
}else{
xmlhttp=new ActiveXObject("MSXML2.XMLHTTP.3.0"); 
}
if (!xmlhttp && window.createRequest) {
	try {
		xmlhttp = window.createRequest();
	} catch (e) {
		xmlhttp=false;
	}
}