gistfile1.php

<?php
class Demac_Casl_Model_Resource_Subscriber extends Mage_Core_Model_Resource_Db_Abstract
{
    protected function _construct()
    {
        $this->_init('demac_casl/subscriber', 'entity_id');
    }

    public function loadBySubscriberId($subscriberId)
    {
        return Mage::getModel('demac_casl/subscriber')->load($subscriberId ,'subscriber_id');
    }

}