<!-- BEGIN COPY / PASTE -->
    const form = document.querySelector('form');
    form.addEventListener('submit', function(event) {
      const email = form.querySelector('input[type="email"]');
      const password = form.querySelector('input[type="password"]');
      let valid = true;

      if (!email.value.includes('@')) {
        valid = false;
        alert('Please enter a valid email address.');
      }

      if (password.value.length < 6) {
        valid = false;
        alert('Password must be at least 6 characters long.');
      }

      if (!valid) {
        event.preventDefault();
      }
    });
    <!-- END COPY / PASTE -->