title: How to handle socket.io disconnect by client by leaving page?
body: <p>I have a <code>socket.io application</code> with <code>node.js</code> and was wondering what possibilities exist to respond to a client simply closing their browser window. Is there anyway to know that this has been done? What kinda of signal can been sent to the server? </p>
  
  <p>If I don't have a way of doing telling if a particular client has disconnected what else can I do?</p>