ajax进度条

nbsp;           }
            }
        }
       
        function pollServer() ...{
            createXMLHttpRequest();
            var url = "ProgressBarServlet?task=poll&key=" + key;
            xmlHttp.open("GET", url, true);
            xmlHttp.onreadystatechange = pollCallback;
            xmlHttp.send(null);
        }
       
        function pollCallback() ...{
            if (xmlHttp.readyState == 4) ...{
                if (xmlHttp.status == 200) ...{
                    var percent_complete = xmlHttp.responseXML.getElementsByTagName("percent")[0].firstChild.data;
                    var progress = document.getElementById("progress");
                    var progressPersent = document.getElementById("progressPersent");
     progress.width = percent_complete + "%";
     progressPersent.innerHTML = percent_complete + "%";
                    if (percent_complete < 100) ...{
                        setTimeout("pollServer()", 2000);
                    } else ...{
                        document.getElementById("complete").innerHTML = "Complete!";
                        //document.getElementById("go").disabled = false;
                    }
                }
            }
  &nbs