function showLoginForm(rememberMe) {
  Element.show('loginForm') ;
  Element.hide('registrationForm') ;
  if (rememberMe) {
    document.forms['loginForm'].user_password.focus() ;
  } else {
    document.forms['loginForm'].user_username.focus() ;
  }
}

function showRegistrationForm() {
  Element.hide('loginForm') ;
  Element.show('registrationForm') ;
  document.forms['registrationForm'].user_email.focus() ;
}