XHR timeout

[whisher]

E' un po datata ma tanto per
darti l'idea:

var maxSecondsWait= 5;
var timeOutCheckWait= 500;
var timeoutMsg1= 'Il server tarda a rispondere!';
var timeoutMsg2= 'Ritentare fra qualche secondo o segnalare il problema all assistenza';
function XHConn(){
    var xmlhttp = null;
    var result= true;
    var browser = navigator.userAgent.toUpperCase();
    if(typeof(XMLHttpRequest) === "function" || typeof(XMLHttpRequest) === "object"){
                xmlhttp = new XMLHttpRequest();
    }
    else if(window.ActiveXObject && browser.indexOf("MSIE 4") < 0){
        if(browser.indexOf("MSIE 5") < 0){
            xmlhttp = new ActiveXObject("Msxml2.XMLHTTP");
        }
        else{
            xmlhttp = new ActiveXObject("Microsoft.XMLHTTP");
        }
    }
    if (xmlhttp===null){result= false;}
    this.connect = function(sURL, mMethod, sVars, fnDone, fnError){
        var callupDate = new Date();
          var callupStart = callupDate.getTime();
          var checkWaitInitialized = false;
        var checkSpentTime=function(){};
          var maxWait;
        var timeoutID= 0;
        var sMethod = mMethod.toUpperCase();
        xmlhttp.open(sMethod, sURL, true);
        xmlhttp.setRequestHeader("connection", "close");
        if(sMethod == "POST"){
            xmlhttp.setRequestHeader("Method", "POST "+sURL+" HTTP/1.1");
            xmlhttp.setRequestHeader("Content-Type","application/x-www-form-urlencoded");
            xmlhttp.setRequestHeader('Content-Length', sVars.length);
        }
        xmlhttp.onreadystatechange = function(){
            if (xmlhttp.readyState == 4){
                if(xmlhttp.status == 200){
                    window.clearTimeout(timeoutID);
                    fnDone(xmlhttp);
                   }
                else{
                    fnError(xmlhttp);
                }
            }
            else if(!checkWaitInitialized){
                maxWait= maxSecondsWait * 1000;
                checkSpentTime= function(){
                    callupDate = new Date();
                    if((callupDate.getTime() - callupStart) > maxWait) {
                        //Expired time!!
                        xmlhttp.onreadystatechange= function(){return;};
                        xmlhttp.abort();
                        alert(timeoutMsg1);
                        alert(timeoutMsg2);
                          location.reload(true);
                    } 
                    else {
                        timeoutID= window.setTimeout(checkSpentTime, timeOutCheckWait);
                    }
                  };
                checkSpentTime();
                checkWaitInitialized = true;
                
              }
        }
        xmlhttp.send(sVars);
    }
    return result;
};
function errorHandler(xhr){
    alert("HTTP error: "+xhr.status);
}
/*
Esempio
function Miafunzione(xhr){
alert(xhr.responseText);
}
var xhr= new XHConn();
if(!xhr){alert(noXhr);return;}
var postVar= 'JSON='+encodeURIComponent(json_encode(values));
xhr.connect(page,'POST',postVar,Miafunzione,errorHandler);
*/