2D Animation with JavaScript (Android). Help!

I really need some help with animation, I've been struggling with understanding animation with JavaScript for two days now. I've been looking for ways to animate my player with a simple walk animation, but can't get it to work. I actually don't even know how to write a script for it... Should I animate through a script, or with Mecanim? And can someone please point me in the right direction with how to write such a script?