asp.net checkbox check/uncheck all with JQuery

html:

<asp:CheckBox CssClass="ChooseAll" Text="Choose all" runat="server" /><br />
<asp:CheckBox CssClass="CheckBoxItem" Text="Checkbox 1" runat="server" /><br />
<asp:CheckBox CssClass="CheckBoxItem" Text="Checkbox 2" runat="server" /><br />
<asp:CheckBox CssClass="CheckBoxItem" Text="Checkbox 3" runat="server" /><br />

jquery:

$(document).ready(function () {
     $(".ChooseAll input:checkbox").change(function ()
     {
         var checked = $(this).attr('checked') || false;
         $(".CheckBoxItem input:checkbox").attr('checked', checked);
     });

     $(".CheckBoxItem input:checkbox").change(function ()
     {
         var checked = ($(".CheckBoxItem input:checked").length == $(".CheckBoxItem input:checkbox").length);
         $(".ChooseAll input:checkbox").attr('checked', checked);
     });
});