I am trying to run this query

Code PHP:
elseif(!empty($_POST['loc']) && $mode == 'location'){
$sql = 'SELECT a.*, u.user_id, u.username, u.user_colour from '.CLASSIFIEDS_TABLE.' a, '. USERS_TABLE .' u 
				WHERE u.user_id = a.ad_poster_id and a.state = '. $location .' and a.ad_expire > '.time().'  ORDER BY a.ad_date DESC';
 
}

but it is giving me this error

Code:
SQL ERROR [ mysqli ]

Unknown column 'AL' in 'where clause' [1054]

SQL

SELECT a.*, u.user_id, u.username, u.user_colour from phpbb_classifieds a, phpbb_users u WHERE u.user_id = a.ad_poster_id and a.state = AL and a.ad_expire > 1242052562 ORDER BY a.ad_date DESC LIMIT 10

I cant figure out why it is doing this, any ideas?