Multiple .Config Files in ASP.NET Web Application

The usage of multiple configuration file makes the application more secure and manageable.
------------------------
Web.config
------------------------

<?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 configSource="WebSetting.config"></appSettings>
<connectionStrings configSource="WebConnection.config"></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">
<assemblies>

</assemblies>
</compilation>
<!--
The <authentication> section enables configuration
of the security authentication mode used by
ASP.NET to identify an incoming user.
-->
<authentication mode="Windows"/>
<!--
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>
-->
</system.web>

</configuration>


------------------------
WebSetting.config
------------------------

<connectionStrings>
<clear/>
<add name="ConnectonString" connectionString="Data Source=;Initial Catalog=;Persist Security Info=True;User ID=;Password=;Min Pool Size=5;Max Pool Size=500;Connect Timeout=500;Pooling=true;MultipleActiveResultSets=False;Packet Size=4096;Application Name="Microsoft SQL Server Management Studio"" providerName="System.Data.SqlClient"/>
</connectionStrings>


------------------------
WebConnection.config
------------------------

<appSettings>
<add key="Foo" value="External Web Config" />
</appSettings>