$this->addColumn('race_name', array(
            'header'    => Mage::helper('catalog')->__('Category'),
            'index'     => 'race_name'
        ));

		$this->addColumn('ticket_name', array(
            'header'    => Mage::helper('catalog')->__('Ticket Category'),
            'index'     => 'ticket_name'

		));