ASP.NET - Forms authentication user impersonation

<?xml version="1.0"?>
<!-- 
    Note: As an alternative to hand editing this file you can use the 
    web admin tool to configure settings for your application. Use
    the Website->Asp.Net Configuration option in Visual Studio.
    A full list of settings and comments can be found in 
    machine.config.comments usually located in 
    \Windows\Microsoft.Net\Framework\v2.x\Config 
-->
<configuration>
	<appSettings/>
	<connectionStrings/>
	<system.web>
		<!-- 
            Set compilation debug="true" to insert debugging 
            symbols into the compiled page. Because this 
            affects performance, set this value to true only 
            during development.
        -->
		<compilation debug="true"/>
		<!--
            The <authentication> section enables configuration 
            of the security authentication mode used by 
            ASP.NET to identify an incoming user. 
        -->
		<authentication mode="Forms"/>
		<!--
            The <customErrors> section enables configuration 
            of what to do if/when an unhandled error occurs 
            during the execution of a request. Specifically, 
            it enables developers to configure html error pages 
            to be displayed in place of a error stack trace.

        <customErrors mode="RemoteOnly" defaultRedirect="GenericErrorPage.htm">
            <error statusCode="403" redirect="NoAccess.htm" />
            <error statusCode="404" redirect="FileNotFound.htm" />
        </customErrors>
        -->
		<membership defaultProvider="AspNetReadOnlyXmlMembershipProvider">
			<providers>
				<add name="AspNetReadOnlyXmlMembershipProvider" type="ReadOnlyXmlMembershipProvider" description="Read-only XML membership provider" xmlFileName="~/App_Data/Users.xml"/>
			</providers>
		</membership>

    <pages>
      <controls>
        <add tagPrefix="asp" namespace="System.Web.UI.WebControls" assembly="FormsAuthenticationUserImpersonation" />
      </controls>
    </pages>
	</system.web>
  <location path="Private">
    <system.web>
      <authorization>
        <allow users="Alice" />
        <deny users="*" />
      </authorization>
    </system.web>
  </location>
</configuration>