Create multiple check boxes popup dialog box --- use mixed-in Java code

if this is not sufficient for you
http://sikulix-2014.readthedocs.io/en/latest/interaction.html#select

... then you have to integrate the respective Java code into your script (make a def, that sets up and displays a respective Java GUI element)

This is possible rather easy for a medium level Java programmer, but might not be acceptable for a newbee.

depending on the number of check boxes a simple solution with an input dialog might be sufficient:
- in the message display the numbered options line by line
- the user selects by giving the number(s) as answers
- separate the result using split()

Thank you..