VBScript does not natively support "Includes". However, SystemScripter does. With Includes, you can create your own script libraries, recycle code and keep your scripts easy to read and maintain. Here's how it works:

First, create your script library. A script library is a simple script that defines one or more procedures or functions. For simplicity, let's assume you created the following script and saved it as c:\library1.vbs:

Whenever you need a random number, you would either have to copy and paste your function into your script, or you use includes. For that, you just put this statement into your script:

SystemScripter automatically generates the Include procedure that is necessary to read in your external script code. But that's not all. SystemScripter also discovers all procedures and methods in your script library and supports them. So when you enter GetRandom and press TAB, the function name is auto-completed, and SystemScripter shows the correct Info Tooltip:
 

You can use as many external script libraries as you like. Just include them all using the new Include procedure SystemScripter added to your script. And since it is plain VBScript, your include mechanism works everywhere. SystemScripter helped you create the includes, but the result is a standard script.

You can even debug includes.