var xmlhttp = false;
        
// If the user is using Mozilla/Firefox/Safari/etc
if (window.XMLHttpRequest) {
  //Intiate the object
  xmlhttp = new XMLHttpRequest();        
  if(xmlhttp.overrideMimeType){               
    //Set the mime type
    xmlhttp.overrideMimeType('text/xml');
  }            
} else if (window.ActiveXObject) {
  //Intiate the object
  xmlhttp = new ActiveXObject("Microsoft.XMLHTTP");
}