This problem should be pretty straightforward, but I'm new to these methods.

In short, this is what I would like to accomplish: I want to trigger an animation that moves a div a specified number of pixels. That's it. Let's imagine I have buttons on the screen representing each keyboard arrow. Each time you click an arrow the box would move from its current position a specified number of pixels in the appropriate direction.

I originally accomplished this using a transition, but it only works once. I've been searching for the answer to this very BASIC problem for a few hours now and am sincerely frustrated.

Please answer with basic javascript. I'd prefer to not use external libraries for this project.

(edit)
I'm not asking how to accomplish this across all browsers. I'm asking how to accomplish it in any browser.