function GM_registerMenuCommand(menuText, callbackFunction);
menuText is a string, the text of the menu item to add.
callbackFunction is a function object. When the menu item is selected, the
callbackFunction function is called.
This function was introduced in Greasemonkey 0.2.6. You should test whether it exists and degrade gracefully if it does not.
- POST Interceptor adds menu items to toggle whether the script is active.