I\'m making an extension for safari I created a context item with command = showNote
In debugger I get the follwing error TypeError: Result of express
Just ran into this problem myself trying to create a toolbar command. Turns out I was putting the JS in the wrong place. I added it to the "Injected Extension Content" as a start script. Needed to create an HTML page that included the JS and set that as the Global Page File.
Switch that around and you should be set, assuming it's the same problem I just ran into.