title: How to validate jQuery UI combobox values with jQuery Validation Plugin?
body: <p>I've added jQuery UI combobox with remote source to my form. Now, I am trying to validate that with jQuery Validation Plugin (only values from the list are allowed, field is mandatory).</p>
  
  <p>I've tried standard approach:</p>
  
  <pre><code> $("#myform").validate({
      focusInvalid: false,
      focusCleanup: true,
      rules: {
        cbCountry: { // combobox
          required: true
        }
  </code></pre>
  
  <p>But still empty values are allowed. What am I doing wrong?</p>
  
  <p><strong>Update</strong>: I've tried to follow @Mike_Laird's advice below and I've found that my custom method</p>
  
  <pre><code>$.validator.addMethod('validComboboxValue', function (value) {
  },
  ...
  </code></pre>
  
  <p>even not called when applied to jQuery UI combobox. But when I assign the same method to standard text input, it is called.</p>