title: regex expressions prevent sql/script injection
body: <p>I am trying to create a regex expression for client side validation (before server side validation which will also take place) to <strong>prevent sql/script injection</strong> i.e something like this - which <strong>does not</strong> work </p>
  
  <pre><code>(script)|(&amp;lt;)|(&amp;gt;)|(%3c)|(%3e)|(SELECT) |(UPDATE) |(INSERT) |(DELETE)|(GRANT) |(REVOKE)|(UNION)|(&amp;amp;lt;)|(&amp;amp;gt;)
  </code></pre>
  
  <p>What is the correct format for this (above) expression so I can get it to work? </p>
  
  <p>e.g. my EMail checker is like this </p>
  
  <pre><code>(/^[^\\W][a-zA-Z0-9\\_\\-\\.]+([a-zA-Z0-9\\_\\-\\.]+)*\\@[a-zA-Z0-9_]+(\\.[a-zA-Z0-9_]+)*\\.[a-zA-Z]{2,4}$/))
  </code></pre>
  
  <p>Oh and if you can think of anything else to add please "shout".</p>