How to diffrentiate between whether assembly is loaded in ASP.Net Context or desktop application context.

Hi,
I am writing an assembly which will be used both in ASP.Net and desktop applications. i have apecific code that i want run only when it is running under asp.net. I dont want to have compile time flags and two different binaries. What is the best way to identify whether my assembly is loaded from a ASP.Net app or an Desktop App. My Assembly will be running in medium trust in ASP.Net case.
 
Thanks,
Tarun Ramsinghani 
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