I'm not fluent in Hebrew by any stretch, but the phrase appears to be "Thank you very much for a happy birthday." And if someone said that to you and you wanted to say "No problem," it would be "en baya."
מזל טוב מאט from right to left of course...
Yom Huledet Sameach = יום הולדת שמח
Hayom yom huledet sheli
Yom Huledet Same'ach
Yom Huledet Sameach Le'Abba Yom Huledet means birthday Sameach means happy and Dad is Abba. Le'Abba means to Dad In Hebrew it's written as: יום הולדת שמח לאבא
You can try www.myhappyplanet.com an internatioal forum of language translation and people wishing to improve their skills in another language. There is a section that you can enter "translate phrase" but i haven't personally tried it.
yom huledet sheló (יום הולדת שלו)
"Yom huledet sa'me'ach, aba" (יום הולדת שמח, אבא).
"YOME hoo-LED-det sah-MAY-ahkh"
yom huledet sameach, abba (יום הולדת שמח, אבא)
matai yom huledet Shel Mark? (מתי יום הולדת של מארק)
Yom huledet same'akh, Arik (יום הולדת שמח, אריק)