socket.io namespace error (Object #<SocketNamespace> has no method 'connect')

socket.io namespace error

   cio = require("socket.io-client")
   io = require("socket.io")



		var manager = io.listen( port );

		manager.of('/chat').on('connection', function (socket) {

			console.log('connecting socket on server');	
		
		});		

		var socket = cio.connect( 'http://localhost:'+port +'/chat' );
	  
		socket.on('connect', function() {
				console.log('connected client ');
		});



		socket.connect( ); // this must be removed, it causes the error because it autoconnects