title: Regular expression issue when validating '/' character
body: <p>I have been having some problems with regular expressions. I want to validate user input when a bus number is entered. </p>
  
  <p>Examples: 37, 37A, 37S, 37A/L, 16A/250, 16A/250K etc</p>
  
  <p>The regular expression I came up with is </p>
  
  <pre><code>(^\d{1,3}[A-Z]{0,3})|(^[\d{1,3}[A-Z]{0,3}\/\d{0,3}[A-Z]{0,3}])
  </code></pre>
  
  <p>It validates 37, 37A, 37S but when it comes to validating 37A/L it fails. Can someone tell me where I am going wrong with this?</p>
  
  <p>Note:I am using a regular expression validator for a text box. I have placed this in the ValidationExpression.</p>