cross script communication

Hi- Im writing a plug in, that I want people to be able to call via script.  Some parts of the plug in are actually scripts themselves, and I wanted to allow the client scripter to call functions inside our scripts.  How do I do this?

I found this snippit in the InDesign Scripting Guide (PDF):

#engine library

export random, libVersion;

const libVersion = "Library 1.0"; function random (max) {
return Math.floor (Math.random() * max);
}

But the ESTK just says that im using export incorrectly (of course this is copy and paste from the PDF).  How do I mark a function as exportable, or how do i call a function betwen scripts of different engines?

Thanks!