title: How to do cross field validation with jQuery?
body: <p>I am seeing a lot of help writing custom jQuery validation for any type of field on my page, but how would I write a custom validation method that takes values from multiple fields into account (cross-filed validation)? I <strong>think</strong> I'm supposed to do <code>$.validator.addMethod</code> to add my custom method and then add a rule to the validator object (instead of to a specific field), but I am having trouble with the syntax. Can anyone help?</p>
  
  <p>For example,</p>
  
  <p>I have two fields: date and time. My form is valid only if: </p>
  
  <ol>
  <li>Both are filled </li>
  <li>The date is not a sunday </li>
  <li>The time is between 6am and 6pm</li>
  </ol>