title: connection fail to connect mongodb in node application
body: <p>I have an error while starting up server with node server.js. The error details are here:</p>
  
  <pre><code>path.existsSync is now called `fs.existsSync`.
  info  - socket.io started
  [Thu, 02 Aug 2012 00:58:27 GMT] INFO Tower development server listening on port 3000
  [Error: Target script does not exist: node_modules/design.io/bin/design.io]
  
  /Users/Drew/test/desert-level-pets/node_modules/tower/lib/tower/server/store/mongodb/database.js:39
              throw error;
                  ^
  Error: failed to connect to [127.0.0.1:27017]
      at Server.connect.connectionPool.on.server._serverState (/Users/Drew/test/desert-level-pets/node_modules/mongodb/lib/mongodb/connection/server.js:473:73)
      at EventEmitter.emit (events.js:115:20)
      at connection.on._self._poolState (/Users/Drew/test/desert-level-pets/node_modules/mongodb/lib/mongodb/connection/connection_pool.js:92:15)
      at EventEmitter.emit (events.js:91:17)
      at Socket.errorHandler (/Users/Drew/test/desert-level-pets/node_modules/mongodb/lib/mongodb/connection/connection.js:387:10)
      at Socket.EventEmitter.emit (events.js:88:17)
      at Socket._destroy.self.errorEmitted (net.js:329:14)
      at process.startup.processNextTick.process._tickCallback (node.js:244:9
  </code></pre>
  
  <p>Can anyone can help me to solve it?
  Thanks,</p>