VAT validity check
<p>I have to build in some VAT formulas in a webpage.
When a user fills in a VAT number, i have to check if it's in the right validity format.</p>

<p>The control for Belgium is already done, but I can't find validity formulas for the Netherlands, France and Luxembourg...</p>

<p>Anyone suggestions?</p>

<p>I use Visual Studio .NET 2008, c#. Visual Basic is fine too :)</p>
