$(document).ready(function() {
    $('[required]').required();
});

{
  // (default) added to each label and field if not filled
  className: 'required',

  // (default) if "false" we will let the browser manage the [required] attributes
  override: true,

  // callback each time we validate a field ("this" is the current field)
  onValidate: function(valid, settings) {
    // do something...
  },

  // callback when we try to submit the form (return "false" to stop submiting, "this" is the current form)
  onSubmit: function(valid, settings) {
    // do something...
  }
}

$('#field').required(options);                // initialization

$('#field').required('validate', onValidate); // check a field

$('#field').required('destroy');              // destroy