Quote Originally Posted by none123
Hello!
I'm just wondering by using a MessageBox,
if the thread is already done how can you be able to close it?
Thanks!
A MessageBox is intended to be dismissed by the user, so whether or not the thread has terminated would not be an issue in this case. When invoking a method using a delegate you call Invoke if you want the call to be synchronous, i.e. wait until the method passed to the delegate completes before continuing, or BeginInvoke if you want the call to be asynchronous, i.e. continue without waiting. I suggest that you do some reading on the subject.