<?php

class Pandi_Layout_Model_Config extends Mage_Catalog_Model_Config {
     /**
     * Retrieve Attributes Used for Sort by as array
     * key = code, value = name
     *
     * @return array
     */
    public function getAttributeUsedForSortByArray() {
        $options = parent::getAttributeUsedForSortByArray();
        if (!isset($options['created_at'])) {
            $options['created_at'] = Mage::helper('catalog')->__('Newest first');
        }
        return $options;
    }
    
    /**
     * Retrieve Product List Default Sort By
     *
     * @param mixed $store
     * @return string
     */
    public function getProductListDefaultSortBy($store = null) {
        return 'created_at';
    }
}