How do I check a membership number is unique before adding it to my database?

[PHP_Idiot]

I'm sure this must get asked a lot but I've searched here and googled but not found any answers yet!

Basically on my site I have an admin section that allows me to allocate new members a membership number, the membership number are broken into 3 sections region,venue,member (01-02-003 but without the -'s).

 

I need the form to check that the new membership entered on it does not already exist in hte database, if it does it needs to stop the submission and throw up an error message. If it's unique the submission can go ahead.

 

Any help would be really appreciated 

[jl5501]

you run a select query with the new member number before doing the insert.

 

If the select query returns any rows, then the member number exists and you can flag the error, else you can go ahead and do the insert.

[PHP_Idiot]

Ah ok that makes sense thanks