Binding.bindingSelectionChanged event (apps for Office)

function addEventHandlerToBinding() {
 Office.select("bindings#MyBinding").addHandlerAsync(Office.EventType.BindingSelectionChanged, onBindingSelectionChanged);
}

function onBindingSelectionChanged(eventArgs) {
    write(eventArgs.binding.id + " has been selected.");
}
// Function that writes to a div with id='message' on the page.
function write(message){
    document.getElementById('message').innerText += message; 
}