Running DNN 4.8.4 and developing with Visual Studio 2005

I can not get my module to display the UpdateProgress control.  I see the control in the VS Studio designer but nothing appears when I run the module.  I made sure the button event is in the UpdatePanel and added a 5 second wait. 

Also. when I click the button, the screen "flashes", page blanks out and then redraws.  I traced in the debugger and see the Page_Load event is a partial page update.

    Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load

        If (Page.IsPostBack) Then Exit Sub   <<<<<<  Exit occurs on UpdatePanel button click

Here are partial source extracts:

1) File mtmc.ascx

<%@ Register Assembly="AjaxControlToolkit" Namespace="AjaxControlToolkit" TagPrefix="cc1" %>


  <asp:UpdatePanel ID="UpdatePanel3" UpdateMode="Conditional" runat="server">
    <ContentTemplate>
        <asp:GridView ID="gv1" runat="server">
        </asp:GridView>
        <br />
        <asp:Button ID="Button3" runat="server" OnClick="Button3_Click" Text="Button" /><br />
        <br />
        <asp:UpdateProgress ID="UpdateProgress3"  AssociatedUpdatePanelID="UpdatePanel3" runat="server">
            <ProgressTemplate>
                Loading ...
            </ProgressTemplate>
        </asp:UpdateProgress>
        <br />
    </ContentTemplate>
</asp:UpdatePanel>

2) Code behind mtmc.ascx.vb

Protected Sub Button3_Click(ByVal sender As Object, ByVal e As System.EventArgs)

        System.Threading.Thread.Sleep(5000)
        Call popGV()

    End Sub

    Private Sub popGV()

        Me.gv1.DataSource = Nothing


        Dim myDataTable As DataTable = New DataTable("AdditionalCodes")

        Dim myDataColumn As DataColumn
        Dim myDataRow As DataRow

        myDataColumn = New DataColumn
        myDataColumn.DataType = System.Type.GetType("System.String")
        myDataColumn.ColumnName = "hours"
        myDataColumn.Caption = "Hours"
        myDataColumn.Unique = False
        myDataTable.Columns.Add(myDataColumn)

        myDataColumn = New DataColumn
        myDataColumn.DataType = System.Type.GetType("System.String")
        myDataColumn.ColumnName = "proccode"
        myDataColumn.Caption = "Procedure Code"
        myDataColumn.Unique = False
        myDataTable.Columns.Add(myDataColumn)

        myDataRow = myDataTable.NewRow()
        myDataRow("hours") = "12"
        myDataRow("proccode") = "Load: " + DateTime.Now.ToString()
        myDataTable.Rows.Add(myDataRow)

        Me.gv1.DataSource = myDataTable
        Me.gv1.DataBind()

    End Sub

Thanks help.

1) That was it.  Adding ScriptManager in Page_Load

        If DotNetNuke.Framework.AJAX.IsInstalled Then
            DotNetNuke.Framework.AJAX.RegisterScriptManager()
        End If

        If (Page.IsPostBack) Then Exit Sub

Thanks.

2) Follow-up:  How do I get the ProgressTemplage "gif" file to appear.  I see the gif  file in Visual Studio Designer window, but when I run I see the IMG ALT string: "ABC Loading"

What is the proper way to specify "SRC" path that would always work if I move or rename the website?

        <asp:UpdateProgress ID="UpdateProgress1"  AssociatedUpdatePanelID="UpdatePanel1" runat="server">
        <ProgressTemplate>
                 <img alt="ABC" src="../../images/Indicator-circleball.gif" />&nbsp;Loading ...
        </ProgressTemplate>

- Thx

With ResolveClientUrl, the image appears  (sometimes) the first time.  Afterwards the ALT string appears.  While researching, I found a similar function ResolvetUrl which displays the image all the time.

http://www.andornot.com/about/developerblog/2007/06/resolveurl-vs-resolveclienturl.aspx

Thanks for your help.