Regular Expressions

For a reference to be valid, the server-side should validate the reference to the same format as the client-side, plus the following additional constraints: the four letter group must be one of ACFT, ABQR, BXDE. Anything else is invalid. The next character must be a hyphen. Anything else is invalid.

The first digit may only be 1 or 2. The other digits may be any value between 0 and 9 inclusive.

My code below that needs help so it matches with what is asked above. Can i have help plz.

if (isset($webdata['bookingreference'] )) {

if (!preg_match("/^[a-z A-Z]{4}-[0-9]{5}$/",$webdata['bookingreference'])) {

$formerror['bookingreference'] = 'Not valid on server: invalid bookingreference format ';

//echo "invalid bookingreference format";

$valid = FALSE ;