OnBeforeUnLoad

OnBeforeUnLoad.js

// include EventListener https://gist.github.com/rbarros/6c7888320ee0cdc3bab7
// include Ajax https://gist.github.com/rbarros/2776240
function OnBeforeUnLoad(e) {
    e.preventDefault();
    var ajax = Ajax.open({
        method: 'GET',
        url: 'http://localhost/',
        dataType: 'json',
        //data: { id: 1 },
        success: function (json) {
          console.log(json);
        }
    });
    return 'Realmente deseja sair ?';
}
EventListener.addEvent(document.getElementsByTagName('a'), 'click', function () {
   OnBeforeUnLoad = function() {};
});
EventListener.addEvent(document.getElementsByTagName('input'), 'submit', function () {
   OnBeforeUnLoad = function() {};
});
window.onbeforeunload = OnBeforeUnLoad;