magento 1.9 – How to solve a PHP fatal error: class & # 39; Eltrino_DiamanteDesk_Helper_Data & # 39; it is not found in /home/abc/public_html/app/Mage.php on line 547

My extension code:

Path : application / code / community / Eltrino / DiamanteDesk / Helper

<? php
/ **
* Copyright (c) 2014 Eltrino LLC (http://eltrino.com)
*
* Licensed under the open software license (OSL 3.0).
* You can not use this file, except in compliance with the License.
* You can obtain a copy of the license in
*
* http://opensource.org/licenses/osl-3.0.php
*
* If you did not receive a copy of the license and can not
* get it through the worldwide network, please send an email
* to license@eltrino.com so we can send you a copy immediately.
* /

The Eltrino_DiamanteDesk_Helper_Data class extends Mage_Core_Helper_Abstract
{
const XML_PATH_DIAMANTE_DESK_API_USERNAME = & # 39; diamantedesk / api / username & # 39 ;;
const XML_PATH_DIAMANTE_DESK_API_KEY = & # 39; diamantedesk / api / key & # 39 ;;
const XML_PATH_DIAMANTE_DESK_API_SERVER_ADDRESS = & # 39; diamantedesk / api / server_address & # 39 ;;
const XML_PATH_DIAMANTE_DESK_BRANCH_CONFIGURATION_BRANCH = & # 39; diamantedesk / branch_configuration / branch & # 39 ;;
const XML_PATH_DIAMANTE_DESK_CONFIGURATION_FOOTER_LINK_URL = & # 39; diamantedesk / configuration / footer_link_url & # 39 ;;

Public function getSupportLink ()
{
returns Mage :: getStoreConfig (static :: XML_PATH_DIAMANTE_DESK_CONFIGURATION_FOOTER_LINK_URL);
}
}

Note : Magento return Order blank page

How can I solve the problem?