Display a progress bar while loading a report!

Hello all,
My report page in ASP.NET named GenerateReport.aspx took a while for loading data, therefore I would like to add some code from behind to display a progressbar from another page ProgressBar.aspx while continue loadding the report. In the code behind of page_load for GenerateReport.aspx page as following:
        Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
              Response.Redirect("ProgressBar.aspx", False)

              ' codes to display a report
               .....
        End Sub
 
I used above Response.Redirect but the progressBar load but not report. Any missing code, how I can open the GenerateReport.aspx, it will display the progressBar automatically and continue loading ...