Changing the application name dynamically

Hi,


 I have  requirement ,i need to chnage the application name of the membership and role provider dynamically by using the url.
From one of the forums i have found that ,we can assign the application name from the Application_PreRequestHandlerExecuite.
i have changed the application name successfully,but the event reads all the requests(like request for CSS,Request for images,etc...).
In this process i am unable to get the desired name from the url.
can any one suggest the best place to retrieve the http Url available in the Address bar and ignore the all other requests.

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