What does this code mean?

okay so what i want to know first is what does this code say? and mean?

_root.lk = false;

Second what i am trying to do is i have a flash www.acs2design.net what i want to do is on the last three they are supposed to be different not the same and i cant get the code to grab the right movie clip if anyone can help me out i would appreciate it please help.