the code i think your talking about is the :"action": code so itd be like :"wink": (without the quotations) or w.e well thats how you put in a smiley. however if you dont want to learn the codes, then just click the happy face and choose which one you like. and when you click one the code will come up in the text for that smiley, but once you hit post, then the smiley will appear. and youll also see the code when you put your mouse on the smiley.
so basically. you have to put the codes in for the smileys to work.