text: chrome.runtime.onMessage.addListener( function(request, sender, sendResponse){
      var click_event = new MouseEvent('click', {
          'view': window,
          'bubbles': true,
          'cancelable': true
      });
      switch(request.action){
          case 'NEXT-MK':
              document.getElementById('play-next').dispatchEvent(click_event);
              break;
          case 'PREV-MK':
              document.getElementById('play-prev').dispatchEvent(click_event);
              break;
          case 'PLAY-PAUSE-MK':
              document.getElementById('play-pause').dispatchEvent(click_event);
              break;
      }
  });