code: function getTimestamps() {
  					try {
  						var trans = db.transaction(['save'], "read"),
  						store = trans.objectStore('save'),
  						request = store.getAll();
  						request.onsuccess = function (e) {
  							var i = 0, a = event.target.result, l = a.length;
  							for (; i < l; i++) {
  								timestamps[a[i].key] = a[i].timestamp;
  							}
  						};
  					}
  					catch (e) {
  					}
  				}
docs: get all the timestamps for existing keys