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!"); } );     } ) ); } );