>Thanks for yuour replies.
>I went ahead and changed a .cs file , did an IISRESET, and changes seemed to take effect.
>So the .cs file must be run in real time ?
>I realise thai is not the most ideal way but I was just curious !!

I think this is what we call In-Place compilation. But, I would definitely suggest to remove those from the server and only use a DLL. This is better for security, provides less files to maintain, faster to update and usually is required by the security of the corporate standard to avoid those source files to be stored on the server.