Display a list of users using mongodb using node.js and HTML

First the index.js

var mongoose = require('mongoose');
var express = require('express');
var router = express.Router();

router.post('/adduser', function (req, res) {
var db = require("../db");
var userName = req.body.username;
var userEmail = req.body.useremail;
var Users = db.Mongoose.model('usercollection', db.UserSchema, 'usercollection');
var user = new Users({ username: userName, email: userEmail });
user.save(function (err) {
    if (err) {
        console.log("Error! " + err.message);
        return err;
    }
    else {
        console.log("Post saved");
        res.send("Feito");

    }
});
});

Then the HTML div that inserts

<div>
    <h1 class="text-center title-1"> Cadastro de Usu&aacute;rio </h1>
    <form action="/adduser" method="post">
        <p>Username:<input type="text" name="username" /></p>
        <p>Email:<input type="text" name="useremail" /></p>
        <p><input type="submit" value="Salvar" class="button_active" ></p>
    </form>
</div>    

Now below I will post my attempt to display a user

First the .js

router.get('/showuser', function (req, res) {
var db = require("../db");
var userName = req.body.username;
var cursor = db.usercollection.find({'username': userName});
cursor.save(function (err) {
    if (err) {
        console.log("Error! " + err.message);
        return err;
    }
    else {
        console.log("Post saved");
        res.send("Feito");

    }
});

});

Then HTML

<form action="/showuser" method="get">
    <p>Username:<input type="text" name="username" /></p>
    <p><input type="submit" value="Salvar" class="button_active" ></p>
</form>

The browser displays this

I would like some light on how to perform this procedure to display a user from a table using HTML