Are master files a replacement for user controls for overall layout?

[Alan Silver]

However, when I ran a page like this, I got errors from VWD. It

Because you don't have properly formed HTML.

<snip>

I think we are talking at cross purposes here. I am now trying to do a
page that uses a master page, but gets the name of the master page from
web.config instead of from the page directive attribute.

My aspx looks like this...

<%@ Page Language="C#" AutoEventWireup="true" CodeFile="Ferret.aspx.cs"
Inherits="Ferret" Title="Untitled Page" %>
<asp:Content ID="Content1" ContentPlaceHolderID="ContentPlaceHolder1"
Runat="Server">
<p>This is a ferret page. It should use the master page specified in
web.config.</p>
</asp:Content>

and the web.config file specifies the master page to use.

When I try to run this in VWD, it does compile, and does show the page.
When I close the browser and go back to VWD, I see the three errors that
I quoted before. The page displays fine, including the master page
parts. The source contains the html tag, and validates 100% (amazingly
enough!!).

I'm still very confused as to what's going on here. Any further help
would be appreciated. Thanks