I need to increment each new invoice id by 5, i have tried below code.

But changed all invoices, shipments, orders and credit memos.

I need each new invoice id increment by 5, shipments increment by 5 and credit memos increment by 3.

Also sales order increment by 1(normal).

How can i do this ?.

Any one help me.




 

    class Mage_Eav_Model_Entity_Increment_Numeric extends Mage_Eav_Model_Entity_Increment_Abstract    
    {
       public function getNextId()
        {
            $last = $this->getLastId();
    
            if (strpos($last, $this->getPrefix()) === 0) {
                $last = (int)substr($last, strlen($this->getPrefix()));
            } else {
                $last = (int)$last;
            }
    
            $next = $last + 5;
    
            return $this->format($next);
        }
    }