Turn on motion blur for all comps in one shot

Should be pretty straightforward:

function enableMotionBlur(){
	for (var i = 1; i <= app.project.numItems; i++){
		var comp = app.project.item(i);
		if (comp instanceof CompItem){
			for (var j = 1; j <= comp.numLayers; j++){
				if (comp.layer(j) instanceof AVLayer){
					comp.layer(j).motionBlur = true;
				}
			}
			comp.motionBlur = true;
		}
	}
}
enableMotionBlur();