What should I say when I ask him out?

So I work with this guy who's incredibly sweet but also very shy. I've had a crush on him for a bit and I'd like to ask him out. We both work in the box office at a movie theater and I'd like to ask him out by showing up when he's working and holding up a little message against the glass that asks in a sweet way if he would go out with me (not while there's customers of course lol). But I'm not very eloquent and was wondering if I could get some help on what the note should say. I just want something that basically says "I like you. will you go out with me?". And no I don't want it to just say that. It's gotta be something sweet that won't scare him off.