Set Default Page in Asp.net / ASP.NET Web Application. How do I change the default page when app is enetered

<configuration>
   <system.webServer>
      <defaultDocument enabled="true">
         <files>
            <add value="login.aspx" />
         </files>
      </defaultDocument>
   </system.webServer>
</configuration>

Above code is useful when we have a login page of web application

 and we want directly move to login page when we write

 domain name only. 

Suppose we have domain www.abc.com, when we write www.abc.com 

it will redirect to www.abc.com/login.aspx automatically.