Validate (bassistance plugin) required( dependency-callback ) question

Validate (bassistance plugin) required( dependency-callback ) question

On my client registration form I have the following rules

  1. // Define the div containing validation messages
    var container = $('#clientErrorWrapper');
    // Start validation routine    
    // validate the form when it is submitted
    var validator = $("#frmEdit").submit(function() {
        // update underlying textarea before submit validation
        tinyMCE.triggerSave();
        }).validate({
        errorContainer: container,
        errorLabelContainer: $("ul", container),
        wrapper: 'li',
        // start rules (add new rules as necessary)
            rules: {
                firstname: {
                    required: true
                },
                lastname: {
                    required: true
                },
                email: {
                    required: true
                },
                address1: {
                    required: true
                },
                city: {
                    required: true
                },
                state_province: {
                    required: function(element) {
                        return $("#country").val() == 'US';
                      }
                },
                postcode: {
                    required: true
                },
                country: {
                    required: true
                }
        // finish rules
        }







































I would like to extend the state_province rules so that this field is required if country equals CA or AU as well, how can I achieve this please.