Validation spanning a group of text boxes

Question

I'm trying to achieve the following:

Where:

• Surname is always required
• NI Number OR Reference Number is required

Is this beyond the scope of the ASP.NET Validation Controls? The only solution I can think of is writing some bespoke javascript (for client side) and backing that up with some server side code.

Answer 1

One thing you can try is to have a CustomValidator(see here) check that both textboxes are not empty. Then validate both textboxes with a regular expression. The expression should check for either a valid entry OR a blank field.