title: Jquery stop form submit unless checkbox selected
body: <p>I've got this code, but it doesn't seem to return true. The alert always shows up. Any thoughts (without needing to create a var in which to store that a checkbox has been selected as that just seems a bit hacky).</p>
  
  <p>Thanks.</p>
  
  <pre><code>$("#form").submit(function(e) {
      $('input[type=checkbox]').each(function () {
          if(this.checked){
              return true;
          }
      });
      alert("Please select at least one to upgrade.");
      return false;
  });
  </code></pre>