function tryLogin() {
    var url = '/secure/' + $('username').value + '/';
    new Ajax.Request(url, {
      username: $('username').value,
      password: $('password').value,
      method: 'get',
      onSuccess: function(transport) {
      document.location.href=url;
      },
      onFailure: function(transport) {
      alert("Invalid username or password.");
      }
    });
}