Well, I know the post here is very old !!! There're already much sufficient clues here to solve the mission. Didn't read all posts here actualy but afterall here's a simple, silly, childish trick I used to solve almos all of the js missions. It's a so sufficient trick that I told myself "hey, you ! You are cheating kid. Be a man and do the effort the mission intended to make you do".
Much talk. Anyway here it is :::
Well, the script says, (pseudocode : if the input == x then congratz !!). You then search for what x may be. Well why not just ask the browser to tell you what x is ?! If you're using ff 5, open the web developer and ask the browser to alert x. ((LOLZ, SO EASY)). If not just copy the source and add a js line to alert x.
Used it to pass most js missions. Really helped much on mission 7.
Enough talk, you should do some effort though. Try to understand the trick in the script even if you used my trick. It's not about points, you're trying to learn something, right ??!
~~ ""Getting information off the internet is like taking a drink from a fire hydrant"" ~~