node-postgres get error connect ECONNREFUSED

I want to connect my apps nodejs using node-posgres to PostgreSQL. My apps in localhost (ubuntu) and my postgresql in virtual machine in the cloud with operating system OpenSuse. This is my code :

var express = require('express');
var app = express();


var http = require('http');
var pg = require('pg');

var conString = "postgres://postgres:mypassword@myurl.com:5432/postgres";


app.get('/', function (req, res) {
    res.send('HOLAAAA');
});

// respond with "SERVER" on the homepage
app.get('/server', function (req, res) {

    var client = new pg.Client(conString);
    client.connect(function (err) {
        if (err) {
            return console.error('could not connect to postgres', err);
        }
        console.log('CONNECT PASSED');
        client.query('SELECT * FROM visit', function (err, result) {
            if (err) {
                return console.error('error running query', err);
            }
            console.log('QUERY PASSED');
            console.log(result.rows[0].theTime);
            //output: Tue Jan 15 2013 19:12:47 GMT-600 (CST)
            client.end();
        });
    });

});


var server = app.listen(3000, function () {

    var host = server.address().address;
    var port = server.address().port;

    console.log('Example app listening at http://%s:%s', host, port);

});

But i got an error like this:

could not connect to postgres { [Error: connect ECONNREFUSED]
  code: 'ECONNREFUSED',
  errno: 'ECONNREFUSED',
  syscall: 'connect' }

Please help me how to solve this. Thanks!