Sliding menu which cannot stop

Hi all!

I’ve tried out the tutorial by pom at
Sliding menu: http://www.kirupa.com/developer/flash5/slidingmenu.htm

and it was further developed under
http://www.kirupa.com/forum/showthread.php?t=74700

However, I cannot make the sliding menu to stop. If the user keeps on clicking next it will go on forever. Attached is the swf file regarding the problem.

many thanks!