If specified, the error label is displayed to show a valid element. If a String is given, its added as a class to the label. If a Function is given, its called with the label (as a jQuery object) as its only argument. That can be used to add a text like "ok!".

var options; // Type:  jQuery.validator.options
var instance; // Type:  jQuery.validator
instance = $(".selector").validate(options);

var value; // Type:  string

// Get value
value = instance.success;
// Set value
instance.success = value;

var success : string;