Getting started with Bridge CEP/HTML5 extensions.. need some help

[joe_s66]

I'm stuck with my first Bridge CC 8.0 CEP extension. I'm trying to create an event handler that will trigger in the main.js when a user selects a new thumbnail in the content window and call a function in the extendscript. I've tried a few different options with the following code but nothing appears to work. Thanks for any advice.

	var csInterface = new CSInterface();
	csInterface.addEventListener(document.open,function(e){
	alert("thumbnail selected!");
	});

[Lumigraphics]

It doesn't look like addEventListener is a method for app.document. I do see it listed for window, so maybe look for a mousedown in the document window and check document.selection to see if it has changed? Just guessing here. The Object Model Viewer shows which objects have what methods.