onTrueChange.js

// Implements a works-as-you-expect version of .change on radio buttons
(function ($) {
    $.fn.onTrueChange = function (callable) {
        return this.each(function () {
            var caller = $(this);
            caller.data('cached-value', caller.is(':checked'));
            return caller.closest('form').find('input[name="' + caller.attr('name') + '"]').change(function(){
                if (caller.is(':checked') != caller.data('cached-value')){
                    caller.data('cached-value', caller.is(':checked'));
                    callable.call(caller);
                }
            });
        });
    };
}(jQuery));