disable all form elements inside div

Question

Try using the :input selector, along with a parent selector:

$("#parent-selector :input").attr("disabled", true);

$('#mydiv').find('input, textarea, button, select').attr('disabled','disabled');

For jquery 1.6+, use .prop() instead of .attr(),

$("#parent-selector :input").prop("disabled", true);

or

$("#parent-selector :input").attr("disabled", "disabled");

    $(document).ready(function () {
        $('#chkDisableEnableElements').change(function () {
            if ($('#chkDisableEnableElements').is(':checked')) {
                enableElements($('#divDifferentElements').children());
            }
            else {
                disableElements($('#divDifferentElements').children());
            }
        });
    });

    function disableElements(el) {
        for (var i = 0; i < el.length; i++) {
            el[i].disabled = true;

            disableElements(el[i].children);
        }
    }

    function enableElements(el) {
        for (var i = 0; i < el.length; i++) {
            el[i].disabled = false;

            enableElements(el[i].children);
        }
    }