Extension:Math/modifyMenu.js

/* Any JavaScript here will be loaded for all users on every page load. */  /* Created by Amber Liu /* /* Adds a menu button hello that displays Hello World! */

mw.loader.using( 'ext.math.mathjax.localization', function {   MathJax.Callback.Queue( MathJax.Hub.Register.StartupHook("MathMenu Ready",function {      MathJax.Menu.menu.items[3] = MathJax.Menu.ITEM.COMMAND("hello", function  { alert("Hello World!"); } );     }   ) ); } );