Problem with DLCalendar

Hello,
i use ckeditor in my website for my personal use,
i use a script called dlcalendar available at http://www.dhtmlab.com/ to edit my date inputs forms.
ckeditor make me an error when i use them at same time.
ckedito is ok when i use it alone (remove the dlcalendar script).

Anybody have an idea ?

Thanks
Arnaud