Welcome to 4Mpron, a challenge for your grey brain matter.

If you make it all the way through, you'll get a unique code and an e-mail to send it to. See, we're very interested in brains. We usually hire their owners, too. So let us know.

Answers: Give the page /web/4Mpron/Default.aspx of our web a GET parameter x (PLEASE NOTE: Applies to all levels, NO exceptions). Look for the codes everywhere, anyhow, think out of the box, look up stuff, scrutinize everything closely, find all possible meanings of words. These are riddles, after all.
Oh, and let us know if you get stuck.

Level 1:

We never let our customers stumble in the dark.