So this is a desktop Swing application? If so, what are the "multiple clients" - from where are they connecting through sockets?
I'm not sure where exactly the problem is from your description; if it's in creating a GUI containing a JButton you may want to read up on Swing GUis in general:
http://java.sun.com/docs/books/tutorial/uiswing/index.html
If it's in the multi-threaded client/server socket communication, see
http://java.sun.com/docs/books/tutorial/networking/sockets/index.html
As an aside, JavaRanch is
NotACodeMill, so no one here is going to write the code for you. But we're happy to help if you tell us what you have so far, and where you're stuck making progress.