How To rotate arrows onclick in menu?

How To rotate arrows onclick in menu?

hello,
based on this topic ( https://forum.jquery.com/topic/creating-a-jquery-mobile-menu-with-toggle-submenus ) I create my menu, but I don’t know how to change arrow from ▼ to ►  when its clicked.
can someone tell me?
edit: online demo added: http://jsfiddle.net/sabeti05/4cp9f056/2/