checkbox:全选与反全选

$(document).ready(function () {

    //全选checkbox
    $("#selectAll").click(function () {
        var checked = $(this).prop("checked");
        $(":checkbox").prop("checked", checked);
    });

    $("tbody :checkbox").click(function () {
        var isAllSelected = $("#selectAll").prop("checked");
        var selected = $(this).prop("checked");
        if (!selected ) {
            $("#selectAll").prop("checked", false);
        } else {
            isAllSelected = true;
            $("tbody :checkbox").each(function () {
                if (!$(this).prop("checked")) {
                    isAllSelected = false;
                    return false;
                }
            });
            $("#selectAll").prop("checked", isAllSelected);
        }
    });

});