To find out what stairs you can currently challenge someone in, first go to the Main Stairs Page, then click on "Show your stairs only" link. The ones in BOLD are ones you can make a challenge in. .
VA_M.O.N.E.Y.: You only joined this site 3 or 4 hours ago! Patience!. This is a turn based game site, not LIVE games. You need to expect that people will possibly take the time alotted to them.
And fakar10 is right, people CAN'T turn down Stairs challenges.
And posts of this type are generally frowned upon on Brainking.