function(pref, down, move, up, cancel) {
				_dragStartEvent = pref + down;
				_dragMoveEvent = pref + move;
				_dragEndEvent = pref + up;
				if(cancel) {
					_dragCancelEvent = pref + cancel;
				} else {
					_dragCancelEvent = '';
				}
			}
function(pref, down, move, up, cancel) {
				_dragStartEvent = pref + down;
				_dragMoveEvent = pref + move;
				_dragEndEvent = pref + up;
				if(cancel) {
					_dragCancelEvent = pref + cancel;
				} else {
					_dragCancelEvent = '';
				}
			}
function ( pref , down , move , up , cancel ) { _dragStartEvent = pref + down ; _dragMoveEvent = pref + move ; _dragEndEvent = pref + up ; if ( cancel ) { _dragCancelEvent = pref + cancel ; } else { _dragCancelEvent = '' ; } }
helper function that builds touch/pointer/mouse events
helper function that builds touch / pointer / mouse events
Set the event handlers for the drag operation