Force rule for text box IE make the user put a space

Hi Guys, im looking for some help on making the following work.

At the mo i have a text field that users fill in there Post code / Zip code (depending if your from the UK or not 😉 )

Due to the nature in which the system needs to work i need to make this text box FORCE the user to put a space, IE if a users post code is BR3 1RP i need to make sure they put the space and don’t type it as BR31RP (all one group / word) i understand i cannot dictate where a space will be as all post codes are different however im guessing its simple enough to make the site not submit the form if this is criteria is not met… as i see it all the time with email boxes not submitting if a @ is not used.

any ideas guys, this would be a massive help and i shall love you all forever 🙂

Scott

[closed as duplicate – continue with te original topic http://wordpress.org/support/topic/force-rule-for-text-box-ie-make-the-user-put-a-space-1?replies=1 ]