jquery ui DatePicker

Hi,

is's quite frustrating, I use the jquery ui DatePicker for a valid to
filed on a user form.
Everything seems to be ok, but....
I want to display that a user don't expire and so I save 31.12.9999
(german date format dd.MM.yyyy) in database.
Now I try to edit a user and the init of the form is OK, but the
datepicker input field shows always 31.12.99 (two digits in year)
normally no problem
If I try to save the data I get a validation error, because the internal
representation of the date is 31.12.1999.
After asking google I found a view tips but nothing works for me??

Any help or idea ??

Thanks in advance
Cheers
Dirk