Textbox magically ignores code.

I've never been more frustrated on writing any piece of code.  I have written it 30 different ways and I can't get this to work.  I want a simple textbox with a search button on a master page.  No matter what I do, the textbox seems to revert back to what it was in the previous search eventhough I am now storing the value in session.
 
Headertemplate.ascx
<asp:TextBox ID="SearchTxtBox" runat="server" Width="195px" Font-Size="10pt" Font-Names="Arial Narrow" AutoPostBack="True"></asp:TextBox> <asp:Button ID="Button1" runat="server" Text="Button" /> Code
Partial Class HeaderTemplate Inherits System.Web.UI.UserControl 'holds the redirect string Protected Sub Button1_Click(sender As Object, e As System.Web.UI.ImageCli ...