setting 'expiry date'

I have a php/mysql database with articles. What I need is a php sctipt that will compare the current day with the 'expiry date' entered by the user and if the there is a difference then drop it from the database.. I retrieve the date (called time and format it like this... $query= "SELECT DATE_FORMAT(time, '%d.%m.%Y') AS time, article, id FROM news ORDER BY id DESC"; The expiry date is entered through a javascript widget and is in the format dd/mm/yyyy. thanks, Ross