Hi  jain4,
Refer the below sample. You need to change the paths as per your folder structure.
HTML
MasterPage
<%@ Master Language="C#" AutoEventWireup="true" CodeFile="MasterPage.master.cs" Inherits="MasterPage" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head id="Head1" runat="server">
    <title>Gladrags Admin</title>
    <%-- <link href="adminStyles/admincss.css" rel="stylesheet" type="text/css" />
    <link href="../Admin/uploadify/uploadify.css" rel="stylesheet" type="text/css" />
    <script src="../Admin/uploadify/jquery.uploadify.js" type="text/javascript"></script>--%>
    <link rel="Stylesheet" type="text/css" href="CSS/uploadify.css" />
    <script type="text/javascript" src="scripts/jquery-1.3.2.min.js"></script>
    <script type="text/javascript" src="scripts/jquery.uploadify.js"></script>
    <asp:ContentPlaceHolder ID="head" runat="server">
    </asp:ContentPlaceHolder>
</head>
<body>
    <form id="form1" runat="server">
    <div id="header">
        <span id="cName"></span><span id="Logout1"></span><span class="clear"></span>
    </div>
    <br />
    <div>
        <div id="content">
            <asp:Panel ID="contentPanel" runat="server">
                <div id="rightmenu" class="rightmenu">
                    <div class="menu">
                        <span class="menuheading">Admin Menu</span> <span class="menulinks"><a href="Magzine_covers.aspx">
                            Magazine Cover</a></span> <span class="menulinks"><a href="Addmagzine_Cover.aspx">Add
                                Magazine Cover</a></span> <span class="menulinks"><a href="HOFList.aspx">HOF</a></span>
                        <span class="menulinks"><a href="Addhof.aspx">Add HOF</a></span> <span class="menulinks">
                            <a href="news_and_eventlist.aspx">News & Events</a></span> <span class="menulinks"><a
                                href="Addnews_and_events.aspx">Add News & Events</a></span> <span class="menulinks">
                                    <a href="Bannerlist.aspx">Banners</a></span> <span class="menulinks"><a href="Addbanner.aspx">
                                        Add Banner</a></span> <span class="menulinks"><a href="PhotoGallery.aspx">Photo Gallery</a></span>
                        <span class="menulinks"><a href="AddGalleryPhotos.aspx">Add Image in Gallery</a></span>
                        <span class="menulinks"><a href="fashionshoot_images.aspx">Fashion Shoot</a></span>
                        <span class="menulinks"><a href="Addfashionshoot_image.aspx">Add Fashionshoot Image</a></span>
                        <span class="menulinks"><a href="Changepassword.aspx">Change Password</a></span>
                        <span class="menulinks">
                            <asp:LinkButton ID="log" runat="server" Text="Logout"></asp:LinkButton></span>
                    </div>
                </div>
            </asp:Panel>
            <div id="maincont" class="maincont">
                <asp:ContentPlaceHolder ID="ContentPlaceHolder1" runat="server">
                </asp:ContentPlaceHolder>
            </div>
            <div class="clear">
            </div>
        </div>
    </div>
    </form>
</body>
</html>
ContentPage
<%@ Page Title="" Language="C#" MasterPageFile="~/MasterPage.master" AutoEventWireup="true"
    CodeFile="CS.aspx.cs" Inherits="CS" %>
<asp:Content ID="Content1" ContentPlaceHolderID="head" runat="Server">
</asp:Content>
<asp:Content ID="Content2" ContentPlaceHolderID="ContentPlaceHolder1" runat="Server">
    <script type="text/javascript">
        $(window).load(function () {
            $("#<%=FileUpload1.ClientID%>").fileUpload({
                'uploader': 'scripts/uploader.swf',
                'cancelImg': 'images/cancel.png',
                'buttonText': 'Select Files',
                'script': 'Upload.ashx',
                'folder': 'uploads',
                'fileDesc': 'Image Files',
                'fileExt': '*.jpg;*.jpeg;*.gif;*.png',
                'multi': true,
                'auto': false
            });
        });
    </script>
    <br />
    <br />
    <a href="javascript:$('#<%=FileUpload1.ClientID%>').fileUploadStart()">Start Upload</a> 
    | <a href="javascript:$('#<%=FileUpload1.ClientID%>').fileUploadClearQueue()">Clear</a>
    <div style="padding: 40px">
        <asp:FileUpload ID="FileUpload1" runat="server" />
</asp:Content>
HandlerPage
<%@ WebHandler Language="C#" Class="Upload" %>
using System;
using System.Web;
using System.IO;
public class Upload : IHttpHandler {
    
    public void ProcessRequest (HttpContext context) {
        context.Response.ContentType = "text/plain";
        context.Response.Expires = -1;
        try
        {
            HttpPostedFile postedFile = context.Request.Files["Filedata"];
            
            string savepath = "";
            string tempPath = "";
            tempPath = System.Configuration.ConfigurationManager.AppSettings["FolderPath"]; 
            savepath = context.Server.MapPath(tempPath);
            string filename = postedFile.FileName;
            if (!Directory.Exists(savepath))
                Directory.CreateDirectory(savepath);
            postedFile.SaveAs(savepath + @"\" + filename);
            context.Response.Write(tempPath + "/" + filename);
            context.Response.StatusCode = 200;
        }
        catch (Exception ex)
        {
            context.Response.Write("Error: " + ex.Message);
        }
    }
 
    public bool IsReusable {
        get {
            return false;
        }
    }
}
AppSetting
<appSettings>
  <add key="FolderPath" value="uploads"/>
</appSettings>
Screenshot
