Hi!
I wouldn't use tez in that sentence:
"Tez dziekuje za twoja pomoc" It sounds quite correct, but I would say:
"Rowniez dziekuje za twoja pomoc".
"Hopefully Pan Cybulski will correct me if I am wrong, but I think "dla" means "for" in the sense of "on behalf of." As in "He translated the letter for me/dla mnie." - Yes, Nancy, you are correct <img src="/images/graemlins/smile.gif" alt="" />