function makeHttpRequest() {

   var http_request = false; 

   if (window.XMLHttpRequest) { // Mozilla, Safari,... 
       http_request = new XMLHttpRequest(); 
       if (http_request.overrideMimeType) { 
           http_request.overrideMimeType('text/xml'); 
       } 
   } 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; 
   } 

   return http_request;

}