CasperJs logging into Salesforce

sfdclogin.casper.js

/*jslint browser: true, regexp: true */
/*global casper, require */

var LOGIN_URL, LOGIN_USERNAME, LOGIN_PASSWORD, casp;

casp = require('casper').create({
     viewportSize: {
          width: 1024,
          height: 768
     },
     verbose: true,
     logLevel: 'warning'
});

if (!casp.cli.has('username') && !casp.cli.has('password')) {
     casp.echo('Usage: $ casperjs sfdclogin.casper.js --username=USERNAME --password=PASSWORD [--prod]').exit(-1);
}

if (casp.cli.has('prod')) {
     LOGIN_URL = 'https://login.salesforce.com/';
} else {
     LOGIN_URL = 'https://test.salesforce.com/';
}

LOGIN_USERNAME = casp.cli.get('username');
LOGIN_PASSWORD = casp.cli.get('password');

casp.start(LOGIN_URL, function () {
     'use strict';

     this.log('Logging in', 'debug');
     this.fill('form', {
          'username': LOGIN_USERNAME,
          'pw': LOGIN_PASSWORD
     }, true);

     this.log('Logged in', 'debug');
});

casp.then(function () {
     'use strict';

     this.echo('We\'re logged in.  Now we can do more stuff like take a screenshot!');
                                                       
     this.waitForSelector('#userNavLabel', function () {
          this.captureSelector('test.png', 'html');
          this.log('saved screenshot of ' + this.getCurrentUrl() + 'to test.png', 'warning');
     }, function () {
          this.die('Timeout reached');
          this.exit();
     }, 12000);
});

casp.run();