>I've a question
> If I have a asp.net aplication and send a thread , if I close de browse the thread follow execute??

Yes. The server has no idea who you are or what the client browser does. Once it gets the request, it disconnects from the client. This is the statelessness of the web and why you need to maintain state by passing a session var, a cookie, URL partameters (a.k.a. license plate) or whatever.

So, if the user close the browser the server doesn't now. It will do the processingbut nobody will be listening on the other side.