Steve probably means "when passed 'E1' or 'E2' etc." Indeed IsNum ('E1') interprets it as zero and delivers TRUE. -- View this message in context: http://free-pascal-general.1045716.n5.nabble.com/Possible-bug-in-Numeric-test-tp5724297p5724319.html Sent from the Free Pascal - General mailing list archive at Nabble.com.