Security token doesn't match, possible CSRF attack.

<?php

class AddItems extends Page {

   public static $db = array(
   );

   public static $has_one = array(
   );

static $icon = "cms/images/famfam-silk/application_view_list";

function getCMSFields() {

$fields = parent::getCMSFields();
$fields->removeFieldFromTab("Root.Content.Main", "Content");

return $fields;

}
}
class AddItems_Controller extends Page_Controller {

public function init() {
parent::init();
}

//add our 'show' function as an allowed URL action
public static $allowed_actions = array(
'MyForm'
);

/**
* Create a form with just a single field.
*
*/
public function MyForm() {
$fields = new FieldSet(
new TextField('Title', '<span class="required"></span>Title')
);
$actions = new FieldSet(
new FormAction(
'doSave',
_t('MyForm.SAVE', 'Save')
)
);
$validator = new RequiredFields(
'Title'
);

$form = new Form(
$this,
'MyForm',
$fields,
$actions,
$validator // optional
);
return $form;
}

public function doSave() {

die('In doSave');
}

public function doDelete() {

die('In doDelete');
}

}