Expressing congratulations

Expressions of congratulations:
Congratulation!
Congratulation on your promotion.
May I congratulate you on winning the contest?
I must congratulate you on your success.
Please accept my warmest congratulations on your wedding day.
I congratulate you on your being admitted in one of the favorite senior high schools in our district.
Please accept my heartiest congratulations.

Respond to congratulations:
Thanks!
Thank you.
Thank you very much.