Creame un Login, en panel

Script
function createLoginPanel():
  return {
    init: function() {
      this.registerEventListeners();
    },
    registerEventListeners: function() {
      var that = this;
      var submitButton = document.getElementById('submit');
      submitButton.onclick = function(event) {
        that.handleSubmitClick(event);
      };
    },
    handleSubmitClick: function(event) {
      event.preventDefault();
      var form = event.target.parentNode;
      var elements = form.elements;
      var username = elements.username.value;
      var password = elements.password.value;
      if (username == 'admin' && password == 'admin') {
        alert('Logged in');
      } else {
        alert('Invalid credentials');
      }
    }
  };
}