app.listen{3000, function }(err) {
          ^

var express = require('express');

var morgan = require('morgan');

var app = express();


app.use(morgan('dev'));


app.get('/', function(req, res) {
  var name = "user";
  res.json("my name is " + name);
});

app.get('/username', function(req, res) {
res.json('user');
});

app.listen(3000, function(err) {
    if (err) throw err;
    console.log("Server is running on port 3000");
});