Ajax not working with MasterPage

Hi,

I have a problem with Ajax which does not work in a master page.

I've added 2 image buttons to a master page and by ckicking them the content page changes.

The problem is that the entier page is refreshing and not just the UpdatePanel control.

This is the code I'm using:

<asp:UpdatePanel ID="UpdatePanel1" UpdateMode="Conditional" runat="server"><ContentTemplate><asp:ContentPlaceHolder ID="ContentPlaceHolder1" runat="server"></asp:ContentPlaceHolder></ContentTemplate><Triggers><asp:AsyncPostBackTrigger ControlID="Applications"/><asp:AsyncPostBackTrigger ControlID="Queries"/></Triggers></asp:UpdatePanel>

protected void pageRedirect(object sender, ImageClickEventArgs e)
        {
            string PostBackControlID = getPostBackControlName().ToString();//find the control which is responsible for the postback
            switch (PostBackControlID)
            {
                case "Applications"://STATUS = NEW (1)
                    Response.Redirect("DMS_Apps.aspx");
                    break;
                case "Queries":
                    Response.Redirect("Queries.aspx");
                    break;
            }
        }

I assume it's the Response.Redirect command which is causing the problem.
Can anyone help me with a solution on how to solve this?

Thanks