title: Identity cards number validation
body: <p>I want to validate National identity card number for my small application.</p>
  
  <pre><code>There are only 9 digits
  there is a letter at the end 'x' or 'v' (both capital and simple letters)
  3rd digit can not be equal to 4 or 9
  </code></pre>
  
  <p>How can I validate this  using visual studio 2010? can I use regular expression to validate this?</p>