Loadvariables IE vs FF

Im having a bit of a weird problem wich I cant figure out myself.

http://www.vintagesworld.be/zooi/loadprob/site.php
If you look at the link above, you will see a word “aanmelden”, if you click that, some textfields will apprear, if you entered some characters in it and press the bleu button ,…NOW the problem, in IE the chars you entered will be lined up in the next screen, but in FF it keeps blank (in FF you will see “blabla”, thats from a php file, but actually the chars you typed there should also appear there.)

So basicly…why does it works in IE and not in FF?

Im sure it dont have anything to do with the cache since I checked and changed a zillion times.

Anyone familiar with this problem ?
thx for reading, and maybe offer a solution :slight_smile:

source files
http://www.vintagesworld.be/zooi/loadprob/site.zip