SQL Error : 1052 Column 'board_id' in where clause is ambiguous

select promotion_id, title, brief, image, price, discount, DATE_FORMAT(startdate, '%d/%m/%Y') as startd, DATE_FORMAT(enddate, '%d/%m/%Y') as endd, DATEDIFF(enddate, now()) as songay, DATE_FORMAT(enddate, '%Y:%c:%e:%k:%i:%s') as ed from promotions_news inner join promotions_board on promotions_news.board_id=promotions_board.board_id where (language_id=2) and (promotions_board.active=1) and (promotions_news.active=1) and (enddate >= NOW()) and (board_id=73) order by promotion_id desc limit 0, 5

Line : 30
File : /home/dinatour/public_html/template/promotion/index.php