A simple YUI3 example to toggle all checkboxes in a given form with the same name. If you create a checkbox with a class="global", any checkbox with the same name will be selected with it.

checkbox-toggle.js

YUI().use('node', 'event-delegate', function(Y) {
    Y.delegate('change',
        function (e) {
            var node = e.target;
            var form = node.ancestor('form');
            form.all('input[name=' + node.get('name') + ']').set('checked', node.get('checked'));
        },
        document.body, 'input[type=checkbox].global'
    );
});