Zhù nǐ kuàilè, ling wài dài wǒ wènhou nǐ de fù mǔ.
祝你快乐，另外代我问候你的父母
I hope you are happy. Please send my regards to your parents. 
Some other related Chinese sentences:
Zhù nǐ shēngtǐ jiànkāng.
祝你身体健康。
Hope you will have good health.
Zhù nǐ tiāntiān kāixīn.
祝你天天开心。
I Hope you will be happy everyday.
Zhù nǐ quánjiā xìngfú.
祝你全家幸福。
Hope you will have a happy family.
Zhù nǐ gōngzuò shùnlì.
祝你工作顺利。
Good luck with your career.