ASP.NET Routing

Question

sir , i am a new .net Developer .

i wants to hide my URL , like "home.aspx" to only " home "

i also use routing table .

like

            RouteTable.Routes.MapPageRoute("New Page","NT","~/WebForm1.aspx");

            RouteTable.Routes.MapPageRoute("Home","Home","~/HomePage.aspx");

            RouteTable.Routes.MapPageRoute("About Us","ABt","~/AboutUs.aspx");

in my global.asax file .

answer me sir how can i hide my url . from othres ?