Using a script as a type

I’m working on my GUI for a game I’m building, and I’ve run into a little problem. I’ve set some variables to script names (in this case TweenRotation from NGUI), and keep getting the error “TweenRotation does not denote a valid type”. I was under the impression you could set a variables type to a script. What am I doing wrong here? Am I missing something syntax-wise?

Are you referencing TweenRotation from a JavaScript? If you’re referencing a class defined in a in a different language, than that script has to be placed in Plugins or Standard Assets, which are compiled first.