code: function(pref, down, move, up, cancel) {
  				_dragStartEvent = pref + down;
  				_dragMoveEvent = pref + move;
  				_dragEndEvent = pref + up;
  				if(cancel) {
  					_dragCancelEvent = pref + cancel;
  				} else {
  					_dragCancelEvent = '';
  				}
  			}
docs: helper function that builds touch/pointer/mouse events