var ajax = {
 "par" : ["url", "callback_function", "return_xml"],

// functions
 "msgBox" : function (r) {
  alert(r.getElementsByTagName("Message")[0].firstChild.nodeValue);
  //alert(r);
 },
 "makeHttpRequest" : function() {
  var http_request = false; 
  if (window.XMLHttpRequest) { // Mozilla, Safari,... 
   http_request = new XMLHttpRequest(); 
   if (http_request.overrideMimeType) { 
    http_request.overrideMimeType('text/xml; charset=ISO-8859-1');
   } 
  } else if (window.ActiveXObject) { // IE 
   try { 
    http_request = new ActiveXObject("Msxml2.XMLHTTP"); 
   } catch (e) { 
     try { 
      http_request = new ActiveXObject("Microsoft.XMLHTTP"); 
    } catch (e) {} 
   } 
  } 
   if (!http_request) { 
       alert('Unfortunatelly you browser doesn\'t support this feature.'); 
       return false; 
   }

   http_request.onreadystatechange = function() { 
       if (http_request.readyState == 4) { 
           if (http_request.status == 200) { 
               if (ajax.par.return_xml) { 
                   eval(ajax.par.callback_function + '(http_request.responseXML)'); 
               } else { 
                   eval(ajax.par.callback_function + '(http_request.responseText)'); 
               } 
           } else { 
               alert('There was a problem with the request.(Code: ' + http_request.status + ')'); 
           } 
       } 
   } 
    var method = 'GET';

   http_request.open(method, ajax.par.url, true); 
   http_request.send(null);
 }
}