Program to check username and password with sgs

sgs.js

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

var sgs = {};

sgs.check = function (username, password, callback) {
    // Login html form data
    var post_data = querystring.stringify({
        '__EVENTTARGET': 'ctl00$PageContent$OKButton$_Button',
        'ctl00$PageContent$UserName': username,
        'ctl00$PageContent$Password': password
    });
    // Send request header
    var post_options = {
        host: 'sgs6.bopp-obec.info',
        port: '80',
        path: '/sgss/Security/SignIn.aspx',
        method: 'POST',
        headers: {
            'User-Agent': 'Node/' + process.versions.node,
            'Content-Type': 'application/x-www-form-urlencoded',
            'Content-Length': Buffer.byteLength(post_data)
        }
    };
    // Set up the request
    var post_req = http.request(post_options, function (res) {
        res.setEncoding('utf8');
        sessionID = res.headers['set-cookie'][0].split('; ')[0].split('=');
        if (sessionID[0] == 'ASP.NET_SessionId') {
            callback(true);
        } else {
            callback(false);
        }
    }).on('error', function (e) {
        callback(false);
    });
    // post the data
    post_req.write(post_data);
    post_req.end();
}

module.exports = sgs;