Hehe,

you're almost there:
Code:

alias CheckIdlers {
  var %chan = #needhelp
  if ($me !isop %chan) { echo -a You are not oped on %chan | return }
  var %a = $nick(%chan,0,r)
  while (%a) {
    if ($nick(%chan,%a,r).idle > 600) { 
      ban [color:red]-ku300 [/color]%chan $nick(%chan,%a,r) 2 Please do not idle on %chan $+ , come back later if you got any questions
    }
    dec %a 
  }
}


Greets