Hello all , I am trying to create url routing like this

http://msdn.microsoft.com/en-us/magazine/dd347546.aspx

but I am having few questions , first why he is adding lines to the web.config , I tested it and it didnt appear that they're doing something as I commented them and nothing major appeared

second I am having this line of code that is crashing var display = BuildManager.CreateInstanceFromVirtualPath(_virtualPath,typeof(Page)) as IProfileHandler;

when casted as ihttphandler it's working , but when I am casting it to iprofilehandler(which is implemeting ihttphandler) it's giving null !