How to properly type "Happy Birthday" to someone?

I think it is more formal to say it with a comma and informal to say it without a comma. This sounds weird, but if I am in a certain mood, let's say that I'm content, not really happy but I'm not bad, I will say it with a comma. But when I am hyper and psyched out of my mind I will just say "HAPPY BIRTHDAY BOB!" I mean depending on what the person's name is, lol. It also depends on how well you know the person. I don't think you would just blurt that out to someone whom you have never really talked to much before.