Trouble with the Orthello plug in for managing sprite sheets

I'm using Orthello and sprite sheets to do 2D animation in Unity. I need to have the animations change in response to player input, when the character is moving around.

But when trying to load in the OTAnimatingSprite script so I can use the built in functions it has set up, but it gives me errors. I'm using the script they have on their site which is:

 anim = OT.ObjectByName("Boy1") as OTAnimatingSprite;

But it gives me this error when I do:

"The name 'OTAnimatingSprite' does not denote a valid type ('not found')."

I'm working in Javascript, and their site says that if I'm using Javascript I should move a folder (due to the way that Javascript loads things). But when I do that all the script associations in their built in objects seem to break and I can't even get the animations to work after that.

Can anyone familiar with Orthello help me on this? It's been frustrating me hugely because their site doesn't go into that much detail on how this all works so I fear my inexperience has me ill equipped to fix it myself.

(If anyone wants to see the actual site it's here)

Thanks very much to anyone who can help a fool with a keyboard and free game engine.