you know that the security model of IE6 has changed 
regarding cookies?

by the way: setcookie will only give error output
if cookie headers can't be added anymore as content
output has already started 

there is no way for setcookie() to find out whether
the client will accept and use the cookie as the
client will resend the cookie beginning with the *next*
request if it accepted it

HTTP is a request based protocol

client sends a request, server sends result back
no further communication is done between them 
during the request, the server just pushes out
its data letting the client deal with it, the
server does *not* recieve any feedback (unless
the connection terminated, it will be signaled
then)

so no way to find out if a cookie will be accepted
at send time

bogusified

and restored the form fields silently overwritten
by unwanted mozilla feature

Sorry, so i'm the wrong place, i only give you another question:
What can be the solution to make cookies work on all clients, should i use a different script and different functions or where i can go to get an answer?
Thank you!