Data not being passed from router to view in Node JS

I have the following Node JS code running fine. However, I can't get the value of fullname passed to the view. I can see the value in console.log, but don't know why it is not being passed to the JADE file.

    var express = require('express');
    var router = express.Router();
    var mongo = require('mongodb');

    var fullname;

    /* GET home page. */
    router.post('/', function (req, res, next) {
        select(function (data) {
            fullname = data.name;
            console.log(data.name);
        });
        var username = req.body.username;
        var password = req.body.password;

        res.render('myPage', {username: username, password: password, fullname: fullname});
    });

function select(callback) {
    var MongoClient = require('mongodb').MongoClient;
    var url = "mongodb://127.0.0.1:27017/mydb";

    MongoClient.connect(url, function (err, db) {
        if (err) throw err;

        // Select record
        db.collection("customers").findOne({}, function (err, result) {
            if (err) throw err;
            console.log(result.name);
            callback(result);
        });
    });
}

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