Category - URL Routing
Here Mudassar Ahmed Khan has explained how to solve ASP.Net URL Routing Problem with external StyleSheets (CSS) and JavaScript (JS) files. The problem happens when different levels of virtual paths are created in URL Routing and thus the external StyleSheets (CSS) and JavaScript (JS) files become inaccessible.
Here Mudassar Ahmed Khan has explained how to implement URL Routing in ASP.Net Web Forms 4.0.

URL Routing is supported in .Net 3.5 SP1 or higher frameworks, if you want to use it in Visual Studio 2008 you will need to install .Net Framework 3.5 Service Pack 1.
Here Mudassar Ahmed Khan has explained how to hide (remove) .ASPX extension in URL in ASP.Net.

There are two ways to do it namely URL Rewriting and URL Routing.
URL Rewrite works in IIS Servers while URL Routing can be implemented within ASP.Net code inside Global.asax file. URL Routing is supported in .Net 3.5 SP1 or higher frameworks.

In this article he has explained how to manipulate URLs by hiding (removing) .ASPX extension in URL using URL Routing in ASP.Net.