I have editted out that particular function but having a full reference manual would be useful.
Moved to the scripting forum... They're more likely to know here.
2. When you are tired of browsing without finding what you need, go to http://jongware.mit.edu. You will see a directory listing of about a dozen folders, each one for a different scriptable Adobe application and version. Select the one you need (for CS6, for example, you'd select http://jongware.mit.edu/idcs6js/
3. .. and up comes a friendly, large, welcome page. Click the section you are interested in for an overview of functions (Text Suite, Color Suite, whatever) and you'll get an alphabetical listing of all classes in that section. Select any of them to view coherent information.
4. Or wander down the page to the "Index" link for an alphabetic list of all classes.
6. If you are on a Windows system, you can download the entire set in easy-to-use CHM format. You can also use this on a Mac, but then you need to download a CHM File Viewer somewhere. On my personal page http://www.jongware.com/idjshelp.html you can find downloadable versions. The big Pro of the CHM version is that a good viewer allows easy access to the full index, as well as free text searching. Highly recommended if you only have an inkling of what you are looking for.
7. 'myGetRandom' is not a standard function (the "my" at the start is actually a dead giveaway). If you read that page you found it on, you can see it defines a function called "myGetRandom" in the very same sample script. It pays to pay attention.