Level 4 is easy. you will figure it out soon.
Level 5 is really tough! Can't even figure out how to proceed to next level.

yes lvl5 is tricky one this time. but when it s solved you willl think "ohh its soo logic!".

Ok, but where do I enter the guesses? I mean in the url?
Pretty challenging one.

Edit: Am I supposed to use something like /?login=
Does it need a url parameter? Because, if yes, then what is the variable?