on *:quit:{ set %time. [ $+ [ $nick ] ] $ctime }
on *:TEXT:!seen*:#:{ if (%time. [ $+ [ $2 ] ] == $null) {
    msg $chan I havn't seen $2 $+ .
  }
  else {
    set %seen. $duration($calc($ctime - %time. [ $+ [ $2 ] ]))
    msg $chan  $2 was last seen here: %seen. ago
    unset %seen.
  }
}