Validating postal codes

Hi, I'm trying to validate a Canadian postal code. I've already written a function; code as follows: if(!eregi('(^[a-z][0-9][a-z][0-9][a-z][0-9]$)',$form["authpstcode"])) { $errors[] = 'You must input a valid Canadian postal code (A9A9A9) postal code if he/she resides in Canada'; $continue = false; } The above works OK if the user enters --> M2M6N6 But fails if the user enters ---> M2M 6N6 (note the space between the two triplets) I want my function to validate either, i.e., allow a space between the two triplets but not enforce it. Any idea on how to modify my test? Thanks, Don