function loadXMLDoc(url,params,method,prefix_function,Id) {
 var req = null;

       if (window.XMLHttpRequest) req = new XMLHttpRequest();
       else if (window.ActiveXObject){
        try{
         req = new ActiveXObject("Microsoft.XMLHTTP");
        }catch(error){
                try{
                 req = new ActiveXObject("Msxml2.XMLHTTP");
                }catch(error){alert(error.description);}
        }
       }


        req.onreadystatechange = function(){processReqChange(req,prefix_function,Id)};
        if(method == "POST"){
         req.open("POST", url, true);
         req.setRequestHeader("If-Modified-Since", "Sat, 1 Jan 2000 00:00:00 GMT");
         req.setRequestHeader("Content-Type","application/x-www-form-urlencoded");
         req.send(params);
        }else{
         req.open("GET",url + '?' + params,true);
         req.setRequestHeader("If-Modified-Since", "Sat, 1 Jan 2000 00:00:00 GMT");
         req.send(null);
        }



}

function processReqChange(req,prefix_function,Id) {

    if (req.readyState == 4) {
       if (req.status == 200) {
           prefix_function(req,Id);
       } else { alert("С запросом возникла проблема."); }
    }

}