How to solve HTTP 302 error in Uploadify

<script type="text/javascript">
                    var auth = "<%= IIf(IsNothing(Request.Cookies(FormsAuthentication.FormsCookieName)),String.Empty,Request.Cookies(FormsAuthentication.FormsCookieName).Value) %>";
                    var ASPSESSID = "<%=Session.SessionID%>";

                    $(window).load(
                        function () {

                            alert(auth);
                            $("#FileUpload1").fileUpload({
                                'uploader': 'scripts/uploader.swf',
                                'cancelImg': 'image/cancel.png',
                                'buttonText': 'Click to Choose Document',
                                'script': 'UploadDocument.aspx',
                                //'scriptData': { 'ASPSESSID': ASPSESSID, 'AUTHID': auth },
                                'scriptData': { 'token': auth },
                                'folder': 'Documents',
                                'hideButton': false,
                                //'wmode': 'transparent',
                                'multi': true,
                                'auto': false
                            });
                        }
                    );
                </script>

Sub Application_BeginRequest(ByVal sender As Object, ByVal e As EventArgs)
    ' Fires at the beginning of each request
    Try
        Dim session_param_name = "ASPSESSID"
        Dim session_cookie_name = "ASP.NET_SessionId"

        If Not HttpContext.Current.Request.Form(session_param_name) Is Nothing Then
            UpdateCookie(session_cookie_name, HttpContext.Current.Request.Form(session_param_name))
        ElseIf Not HttpContext.Current.Request.QueryString(session_param_name) Is Nothing Then
            UpdateCookie(session_cookie_name, HttpContext.Current.Request.QueryString(session_param_name))
        End If
    Catch ex As Exception
    End Try


    Try
        Dim auth_param_name = "AUTHID"
        Dim auth_cookie_name = FormsAuthentication.FormsCookieName

        If Not HttpContext.Current.Request.Form(auth_param_name) Is Nothing Then
            UpdateCookie(auth_cookie_name, HttpContext.Current.Request.Form(auth_param_name))
        ElseIf Not HttpContext.Current.Request.QueryString(auth_param_name) Is Nothing Then
            UpdateCookie(auth_cookie_name, HttpContext.Current.Request.QueryString(auth_param_name))
        End If
    Catch ex As Exception
    End Try


End Sub

Context.Response.ContentType = "text/plain"
    Context.Response.Expires = -1

    Dim token As String = Context.Request.Params("token")
    'Dim token As String

    'If IsNothing(Request.Cookies(FormsAuthentication.FormsCookieName)) Then
    '    token = String.Empty
    'Else
    '    token = Request.Cookies(FormsAuthentication.FormsCookieName).Value
    'End If



    Dim ticket As FormsAuthenticationTicket = FormsAuthentication.Decrypt(token)
    If ticket IsNot Nothing Then
        Dim identity = New FormsIdentity(ticket)
        If identity.IsAuthenticated Then
            Try
                Dim postedFile As HttpPostedFile = Context.Request.Files("")

                Dim tempStr As String = Context.Request.QueryString("")

                Dim savepath As String = ""
                Dim tempPath As String = ""
                tempPath = System.Configuration.ConfigurationManager.AppSettings("FolderPath")
                savepath = Context.Server.MapPath(tempPath)
                Dim filename As String = postedFile.FileName
                Dim filetype As String = postedFile.ContentType

                If Not Directory.Exists(savepath) Then
                    Directory.CreateDirectory(savepath)
                End If

                postedFile.SaveAs(savepath & "" & filename)

                Context.Response.Write(savepath & "" & filename)
                Context.Response.StatusCode = 200

            Catch ex As Exception
                Context.Response.Write("Error: " & ex.Message)
            End Try
        End If
    End If