Code:
alias aban {
  if (!$1) { echo 4 -a * Error: Insufficient Paramters e.g. /aban <nick> or /aban <nick> <reason> }  
  var %x = 1, %y = $comchan($1,0) | while (%x <= %y) { 
    if ($me isop $comchan($1,%x)) { ban -k $comchan($1,%x) $1 5 $2- }
    inc %x
  }
}