How do you evolve a Pokemon on happiness?

u have to use zinc,calcium and the rest on a Pokemon u whant to evolve after that lvl. him up.

make the Pokemon hold the SOOTHE BELL(to get it check http://bulbapedia.bulbagarden.net/wiki/Soothe_Bell#Soothe_Bell)..

and then depending on how many heart of your Pokemon has when you hold it on the profetch). It takes 25 mins from no heart to one heart if you ride a bicycle as fast as you could back and forth, another 25mins from one heart to two. And two heart to two beating heart takes about 36 mins.When it has two beating hearts, the next time it levels up, it will evolve. At least that's how I get my crobat and Blissey. Good luck!