Hello,
I create a cookie in a web page via document.cookie, it takes an arabic value, When I tried to retrieve it in other page, It works well in IE, Safari and Opera, but the text value appears as encoded in Firefox. not in arabic.
can anybody help me to fix this with Firefox

any answer please??

Apparently JS stores data as UTF-16, so when you pull the value and attempt to display it using (I assume) UTF-8, all you get is garbage. (Note - I'm only basing the above statement on the following link. It may be completely incorrect or inaccurate)
This is the only link I could find discussing your problem:
http://coding.derkeiler.com/Archive/PHP/php.general/2006-10/msg00463.html