title: jQuery phone number validation allow spaces, minimum of 8 digits
body: <p>How can I allow spaces within an a numbers only validation, with a minimum of 8 digits?
  Phone numbers are much easier to type in when spaces are allowed. e.g. 0400 123 456, 9699 1234.</p>
  
  <p>Here's my code so far, I've only got the minimum 8 digits validation working:</p>
  
  <pre><code>jQuery.validator.addMethod(
    "phone",
    function(phone_number, element) {
      return this.optional(element) || /^\d{8}$/.test(phone_number);
    },
      "Please enter numbers only"
  );
  </code></pre>