Now that we have page parameters, which have been very good for page building, I believe it would be nice to have the ability to change a page parameter's value to a set value as an option on an On click event.
For example, a container's On click event could change a page's parameter to 'true' or 'false'. This would allow for a page to tell when a certain aspect on a page has been clicked and control Visibility/editability of a different object.