Using Javascript to trigger event in Storyline

I'm using Storyline as a decsision tree for agents and its embedded multiple places in the agent-only knowledgebase.

There are actually multiple decsion trees for different situations in this one published file. There is currently a main menu where agents can click to get to the one they want.

So, here is my question. I want storyline to automatically advance to a particular screen depending on the article that it is loaded from.

Each article has a unique identifier "gen number" so theoretically, Java script could be run when the decision tree is loaded. If a particular gen is identified, a trigger could be set to make it load to a particlar screen.

I had my friend write up the javascript which would return a True value if it was loaded from a particular article.  Assuming this code is correct, my next step would have to be setting it up in Storyline so a trigger would occur and load a particular screen.

Hope that makes sense. Here is the code:

if ("tabGEN85157" == document.getElementsByClassName("TabClassActive")[0].id) { return true; }

So, I know I can enter this a trigger when main screen loads, but then what do I do?