Forms Authentication with Active Directory - Configuration Error..

I am trying to have a login page authenticate to my active directory.  I have gone through the How To @ http://msdn.microsoft.com/en-us/library/ms998360.aspx and I keep getting a configuration error.
I set up my default.aspx and my login.aspx just as the how-to directed.
 Here are the entries that I made into a newly created web.config file (as per the how-to):
<configuration>
    <appSettings/>
    <connectionStrings>
        <add name="ADConnectionString" connectionString="LDAP://myDomain.myForest.com/CN=Users,DC=myForest,DC=myDomain,DC=com"/>
    </connectionStrings>
    <system.web>
...
...
...

        <authentication mode="Forms">
            <forms name=" ...