How to fix Error: listen EADDRINUSE while using nodejs?

Question

If I run a server with the port 80, and I try to use xmlHTTPrequest i get this error: Error: listen EADDRINUSE

Why is it problem for nodejs, if I want t

Answer 1

Another thing that can give this error, is two HTTP servers in the same node code. I was updating some Express 2 to Express 3 code, and had this...

http.createServer(app).listen(app.get('port'), function(){            
  console.log('Express server listening on port ' + app.get('port')); 
});        

// tons of shit.

http.createServer(app).listen(app.get('port'), function(){            
  console.log('Express server listening on port ' + app.get('port')); 
});                                                                   

And, it triggered this error.