Question: I have web service on server! This service is calling from the clients applications!

Now how i can get user name and computer name of clients that using this service, for example if application from Clint1 calling this service i want to get computer name and user name of Clint1?

Many thanks!

Answer: 
You can't reliably, really.

The server variable `REMOTE_HOST` may provide you with it, but in most cases it will be an IP address and it could well be a proxy's IP address. Also - it is something that can be easily spoofed.

Same goes for username (`REMOTE_USER`), unless you use some `WS-Security` mechanism to authenticate the user calling your webservice.
The client will have to be passing this information to the service.