Playing timeline frames in reverse in Flash

1.First declare a boolean variable(reverse) which can be only two values true/false.
2.Add an event listeners for mouse out, mouse over, and then enter frame events to your button instance box_01.
3.When the mouse pointer is actually on the button, the reverse variable value is set to true.
4.When mouse pointer isn’t on the button, the reverse variable value is set to false.
5.Event.ENTER_FRAME will execute the run function continuously. It will executes the run function 20 times per second if the frame rate is 20 fps.
6.The run function will continuously check the reverse value (if it’s true or false).
7.When reverse value is true, it will go to previous frame and when the reverse value is false it will go to next frame.