How to find URL parameters for direct login?

[boyboy400]

Thanks nihil. Apparently in the moment you wanted to visit this site, it had
been down!!!!!!!! It works. I have tried it with all of its partners. Please try it again. The frontpage is black with only two boxes for "Nickname" and "Password" (https://www.secretmj.com). Or you might use: www.manjam.eu if .com and or secretmj are down temporarily!
What I want to know is something like what HTRegz suggested, but a working one like:
ww.mmm.c0m/default.aspx?_VIEWSTATE=aaa&AtbNickname=bbb&MemberSignin1:AtbPassword=111

I have tested some alternatives but without any result. I think when users submit their info by input boxes and pressing "Sign-in" button there must be a way for direct loging in via URL.

I appreciate what you did t34b4g5. It was exactly the reason I didn't post the real URL in my first post. However even if you think it's better to delete the second URL completely, I'm OK with this decision.