How do I add a class to the Open URL action?

I've got a symbol and I want to add the Open URL action to the click state, but I also want to add a class to that code. The click event will open a lightbox and play a Youtube video. I've appended the js files I need to my creationComplete area and all I need to do is add this class on the href.

This is what I've got right now -

window.open("youtube link", "class=voverlay");

It's not working of course. What am I missing?

Thanks.