I'm not sure how to write a script for use in a common event conditional branch

[Joram]

I'm trying to make a skill where, if you use 'stab' and you have the skill 'crossattack', you have a 50% chance of using crossattack as well(you can't use crossattack on it's own). I've gotten that far but I need to be able to check if my rogue(the only one who uses the skill) is using two weapons or not because that's the only way it will 'go off'. I'm pretty sure I can use a script in the conditional branch to check for this but I don't know how to write it. I'm using Guillaume777's Multi-slot equipment script version 6.2.1. If anyone can help me out with this, I would greatly appreciate it.

Thanks in advance
Joram