password door help.

Okay, so I've been playing tekkit, using this mod I searched for a password door code, but every one i try, gives me Attempted to call nil, I've made sure I typed everything correctly, but still didn't work, I looked at the password door code on the wiki, I typed it slowly, same thing, its attempted to call nil, I typed a basic code like

redstone.setoutput ("back", true)
sleep (3)
redstone.setoutput ("back", false)

and it still gives me the same error, is there anything I'm doing wrong..? or am I just forever doomed..

When using

rs.setOutput ("back", true)

Make sure the O is in caps, it should work then

Thank you finally it works :ph34r:/>/>!