title: use router in express
body: <p>I am trying to create some basic express application. I want to use routers in it.
  SO I created router.js where it has</p>
  
  <pre><code>router.route('/a/x').post(x.p)
  router.route('/a/y').post(x.p)
  router.route('/a/z').post(x.p)
  </code></pre>
  
  <p>Now I want to load the router to my index.js</p>
  
  <pre><code>var routes = require('./router.js')
  app.use(?,routes)
  </code></pre>
  
  <p>I am wondering what to keep in this ?</p>