title: Using jQuery Validate plugin to ensure at least one of three checkboxes is checked
body: <p>Using the jQuery Validate plugin, how can I make sure that at least one of three checkboxes has been checked? The best I can do so far is to make all three checkboxes required (which isn't what I want), and my code for getting this far is below.</p>
  
  <p>I tried using <a href="http://jquery.bassistance.de/validate/demo/" rel="nofollow">this example</a> on the jQuery Validate demo page, but that requires the checkbox fields to each have the same name. I'm unable to do this, as these fields are pulled from a CMS and they each need the different names.</p>
  
  <p>I want to keep this within jQuery validate as I've got lots of other fields being validated here (stripped out to keep this example clean) and it's the only way I can validate forms with my limited JS/jQuery knowledge. Thanks in advance for any help with this.</p>
  
  <p>Here's my HTML:</p>
  
  <pre><code>&lt;form class="my_form" method="post" action="/" &gt;
  
    &lt;div&gt;&lt;ul class="form_errors"&gt;&lt;/ul&gt;&lt;/div&gt;
  
    &lt;label&gt;&lt;input class="my_checkbox_group" id="my_checkbox_1" name="my_checkbox_1[]" type="checkbox" value="Yes"&gt; My checkbox 1&lt;/label&gt;
    &lt;label&gt;&lt;input class="my_checkbox_group" id="my_checkbox_2" name="my_checkbox_2[]" type="checkbox" value="Yes"&gt; My checkbox 2&lt;/label&gt;
    &lt;label&gt;&lt;input class="my_checkbox_group" id="my_checkbox_3" name="my_checkbox_3[]" type="checkbox" value="Yes"&gt; My checkbox 3&lt;/label&gt;
  
    &lt;input type="submit" value="Submit" /&gt;
  
  &lt;/form&gt;
  </code></pre>
  
  <p>Here's my JS:</p>
  
  <pre><code>$(".my_form").validate({
    errorLabelContainer: ".form_errors",
    wrapper: "li",
    rules: {
      'my_checkbox_1[]': { required: true },
      'my_checkbox_2[]': { required: true },
      'my_checkbox_3[]': { required: true }
    },
    messages: {
      'my_checkbox_1[]': "This field is required",
      'my_checkbox_2[]': "This field is required",
      'my_checkbox_3[]': "This field is required"
    }
  });
  </code></pre>