Javascript Issue/Question

Apologies if this is a question that has been asked and answered, although I have looked through the forums and didn't see an answer.

Issue: Javascript doesn't seem to be running via "Execute Javascript" action for Triggers.

I was playing  around with doing some very simple calculations (counting clicks then dividing correct by total). Setting up the variables in Storyline by the provided wizard is easy and works great. So, too is displaying values held in those variables.

Execute Javascript appears to be the only avenue to calculate as the "conditions" option is very specific.

Initially, I assumed I'd been clumsy with my typing and that the simple code block had an error in it, so I added alerts into the block to see where it was failing; but, no alerts appear. I then added an alert to execute on the first page of the course so it was free of the calculations code, but still nothing shows nor does an error appear.

Suggestions?

Craig