How can i check European VAT-ID with rlValid.class.php

[Steffen Buschkemper]

Hi Guys,

i have add a field in registration form for european VAT-ID.
Now i have a problem. I must check the VAT-ID.

Here for example a php script that check the european vat.

Only registered members can view the code. 

My questions are follow.
1. For account fields there are some checking conditions (isURL, isDomain, isEmail). How can i add isVatId?
2. How can i add the above code to rlValid.class.php? The key for this field = c_ustid.

Best regards
Steffen