function getFileName() {

            var path = document.getElementById("Main_FileUpload1").value;

            var pos1 = path.lastIndexOf("\\");

            var pos2 = path.lastIndexOf(".");



            var pos = path.substring(pos1 + 1, pos2);

            alert(pos);



            var xhr = createXhr();

            xhr.open("get", "AjaxTest.ashx?name=" + pos, true);

            xhr.setRequestHeader("contentType", "application/x-www-form-urlencoded; charset=UTF-8");

            xhr.onreadystatechange = function () {

                if (xhr.readyState == 4) {

                    if (xhr.responseText == "y") {

                        alert(xhr.responseText);

                    } else {

                        alert(xhr.responseText);

                    }

                }

            }

            xhr.send(null);

        }

<%@ WebHandler Language="C#" Class="AjaxTest" %>



using System;

using System.Collections.Generic;

using System.Linq;

using System.Web;

using System.Web.UI;

using System.Web.UI.WebControls;

using Haiyang.DAL;

using System.IO;