It works for me.
You should use only the “Input:” textarea.
If you edit the source code of the input, it won’t change the real site.
You need to use a kind of technique which is very common in web hacking.
And by executing, it is meant that exactly this code should show up in between the
tags in the source code?
I’m sorry if these questions are dumb, but I really don’t get the exercise, wouldn’t you be completely happy as soon as your code is executed on the site, no matter how exactly you achieved it in the first place? In reality I mean?