What to write on a "congrats" cake?

My bf in the army came home yesterday. He graduated AIT. I don't know what to write on his cake. Last December when he came home, I wrote "Congrats and welcome back home Pvt Torres" but I don't want to write the same things on it. So far I wrote "Congratulations" but the rest I'm stuck. Any Help? It's for his surprise party, Please & Thank you!