Access a script that has NO class?

I have a script I downloaded, and it works great, however it has NO class declaration! I want to access it from another script, to change its variables, but I can't figure out how to use transform.GetComponent to access the script, because without a class delcaration, the script has no name? I tried GetComponent with its file name, but that didn't work. The script is javascript (js). I'm calling it from a C# script. Hopefully that's allowed.