response.redirect and master pages

[AbleJames]

I have the following code in a Master Page code behind as a link (ADA is a class I dim for this page):

  Protected Sub selectOrg_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles selectOrg.Click
    'navigation bar
 
    ADA.SmartRedirect("AnnaChooseContact.aspx?retain=true")
  End Sub

In the ADA class which inherits from System.Web.UI.Page I have:

  Public Function SmartURL(ByVal Destination As String) As String
    If (Destination.IndexOf("?") = -1) Then
      Return Destination & "?InstanceId=" & InstanceId
    Else
      Return Destination & "&InstanceId=" & InstanceId
    End If
  End Function
 
  Public Sub SmartRedirect(ByVal Destination As String)
    Response.Redirect(SmartURL(Destination))
  End Sub

I still get a "Response is not available in this context." error when attempting to perform the Response.Redirect line.

Any ideas why? Does Master Pages have "issues" with this sort of thing?

Thanks!
James