How can I create an UpdateProgress in the codebehind? I need to do this because I would like to wrap it in a CompositeControl.

I tried adding the content to the Controls collection of the UpdateProgress but got an error saying it needed to have a ProgressTemplate. How can I add that? 

The UpdateProgress is not accessible until very late in the page's lifecycle.  It cannot be accessed during Page_Load, _Init, _PreRender, and must be accessed before Page_Unload.  I've only found it accessible in the Page_PreRenderComplete event. 

 Thanks but I am creating the UpdateProgress completely in the CodeBehind and adding it to form1.Controls. I am not trying to access it from CodeBehind. I am creating it.

1    UpdateProgress1 = new UpdateProgress();
2    UpdateProgress1.ID = "UpdateProgress1";

How do I add the ProgressTemplate?

I tried this but got an error saying that the ProgressTemplate is required.

1    UpdateProgress1.Controls.Add(new LiteralControl("Loading..."));

Okay, here's how you do it, but if you want an explanation why, you'll have to wait until I get around to blogging this (hopefully tonight! ). 

Partial Class Default9
    Inherits System.Web.UI.Page

    Protected Sub Page_PreRender(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.PreRender
        ' !!!THIS MUST BE DONE IN THE PRERENDER EVENT!!!
        ' Create the label.
        Dim lab As New Label
        lab.ID = "Label1"
        lab.Text = "Please wait..."

        ' Create the UpdateProgress.
        Dim uprog As New UpdateProgress
        uprog.AssociatedUpdatePanelID = UpdatePanel1.ClientID
        uprog.ID = "UpdateProgress1"

        ' Create the ProgressTemplate based on a class the implements ITemplate.
        Dim value As New MyTemplate
        uprog.ProgressTemplate = value

        ' Add the Label to the UpdateProgress and the UpdateProgress to the form.
        uprog.Controls.Add(lab)
        Form.Controls.Add(uprog)
    End Sub

End Class

' THIS GOES IN YOUR PAGES CODE BEHIND ALSO!
Public Class MyTemplate : Implements ITemplate

    Public Sub InstantiateIn(ByVal container As Control) Implements Web.UI.ITemplate.InstantiateIn
        ' This is empty.
    End Sub

End Class

 Awesome, I'll be sure to try this and let you know right away how it works out.

 This works great in a WebForm. Thanks so much. I will be trying it out in a Composite Control next.

What is your blog url? I will be waiting to read that post. Thanks again!  ***NVM I found the url in your sig.