A basic check box manager that lets you switch all the checkboxes with a class of 'checkboxElementsClass' on or off.

CheckBoxManager.js

        var checkBoxManager = {
            allSelected: false,
            checkBoxes: null,

            init: function ($checkBoxes) {
                var that = this;

                that.checkBoxes = $checkBoxes;
            },

            toggleSelect: function () {
                var that = this;

                var changeCheckBoxAttribute = function (checked) {

                    that.checkBoxes.each(function () {
                        $(this).attr('checked', checked);
                    });
                };

                if (that.allSelected) {
                    changeCheckBoxAttribute(false);
                    that.allSelected = false;
                } else {
                    changeCheckBoxAttribute(true);
                    that.allSelected = true;
                }
            }
        }

        //example of using
        $('document').ready(function () {          
            checkBoxManager.init($('.checkboxElementsClass'));
            
            $('.selectAllCheckBox').click(function (e) {
                checkBoxManager.toggleSelect();
            });
        });