Dick Lockey has written a nice example in Scripts ‘n Tips showing a good use of the Include statement. Include allows you to include other scripts in your code. A good use of this is to keep commonly used subroutines, VBScript code, or dialogs in scripts that you can then Include in your macros, rather than duplicating the code across all the macros that use it. If you ever need to fix or modify this code you then only need to do it once. It also makes your main scripts smaller and easier to read.

Dick’s example provides a function for validating dialog field lengths. Useful in itself.

Read the example here.