Hollywood star Alec Baldwin paid tribute to his actor brother Billy as he turned 50 on Thursday (21Feb13).

The 30 Rock star took to his Twitter.com page to tell followers how proud he is of his younger sibling, who is celebrating his half-century milestone.

In a series of posts, Alec writes, "I want to say happy 50th birthday to my brother Billy, one of the warmest, kindest, most caring people I've ever known. Billy is a great husband and father while maintaining a full load of his work and advocacy-related efforts. No different than many, perhaps, but always done with a combination of good nature, focus and intelligence.

"Happy birthday, Billy. Having you as my brother is one of the things I cherish most in this life."