import newsletter subscriber email list

    public function addOld() {
    	$read= Mage::getSingleton('core/resource')->getConnection('core_read');
    	 
    	$sql ="select * from `old_newsletter` where status = 0";
    	$results = $read->query($sql);
    	$write = Mage::getSingleton('core/resource')->getConnection('core_write');
    	 
    	foreach ($results as $row) {
    		 if (! Mage::getModel('newsletter/subscriber')->loadByEmail(trim($row['email']))) {
    		 	Mage::getModel('newsletter/subscriber')->subscribe(trim($row['email']));
    		 	$sql ="update old_newsletter set status = 1 where email = ?";
    		 	$write->query($sql,array($row['email']));
    		 	var_dump($row['email'] . ' add email successed');
    		 }
    	}
    	
    }