How to know If a girl likes you at work?

So uh I met this girl at work. She seems shy to me. she always walk head down. Every time we see each other she just smiles and look down. She's kinda snob at times and she ignore most of the guys on our work unless someone talks to them. I caught her sometimes looking at me, I dunno maybe waiting for me to smile at her. I'm about to leave at work so Im going to take my chance but I just want to know your thoughts guys?

thanks