title: Beginner PHP. Regular expression, excluding characters
body: <p>I am trying to create a regex for my form that will accept lower case characters a-z, upper case A - Z and all numbers. </p>
  
  <p>I have successfully included what needs to be accepted, but what I want to do is exclude the following characters  <code>$£*</code></p>
  
  <p>The code I have so far is as follows:</p>
  
  <pre><code>if (!preg_match("/^[a-zA-Z0-9 ^$£* ]{1,20}$/", $webdata['familypa']))
  </code></pre>