lementById('drop-remove');
    var calendarEl = document.getElementById('calendar');

    // initialize the external events
    // -----------------------------------------------------------------

    new Draggable(containerEl, {
      itemSelector: '.external-event',
      eventData: function(eventEl) {
        return {
          title: eventEl.innerText,
          backgroundColor: window.getComputedStyle( eventEl ,null).getPropertyValue('background-color'),
          borderColor: window.getComputedStyle(