使用日期php mysql

I am making a reservation module in php

but facing a problem on fetching data i was store a date in d/m/y format..

I want to show upcoming and past reservations for upcoming i was use this query

$cdate = date('d/m/y');
$r = "select * from reservations WHERE uid = $uid AND rdate < '$cdate'";

its working but when the date is more then 10 it;s goes to past reservation i don;t know same thing in in past if date is less then 10 it;s showing in upcoming section....

if you will that will very appropriated..

Thanks Rahul