It's a simple away dialog, you set your away and regular names that you want, (open with /jonsaway).

dialog away {
  title "Jon's Away System"
  size -1 -1 200 200
  box "Away Nick", 1, 5 5 95 65
  edit "", 2, 10 20 85 20
  button "Set Nick", 3, 10 45 85 20
  box "Regular Nick", 4, 100 5 95 65
  edit "", 5, 105 20 85 20
  button "Set Nick", 6, 105 45 85 20
  box "Away Message", 7, 5 70 190 45
  edit "", 8, 10 85 180 20, autohs
  button "Go Away", 9, 5 120 190 20, default
  button "Return", 10, 5 145 190 20
}
alias jonsaway {
  dialog -mv away away
}
on *:DIALOG:away:init:0: {
  did -a away 2 %jonsaway.awaynick
  did -a away 5 %jonsaway.regnick
  did -a away 8 %jonsaway.awaymessage
  if ($true == $away) {
    did -t away 10
    did -b away 9
  }
  else {
    did -b away 10
  }
}
on *:DIALOG:away:sclick:*: {
  if ($did == 3) {
    if ( $did(away,2).text != $null ) {
      set %jonsaway.awaynick $did(away,2).text
      echo -a Away nick set to %jonsaway.awaynick
    }
  }
  if ($did == 6) {
    set %jonsaway.regnick $did(away,5).text
    echo -a Regular nick set to %jonsaway.regnick
  }
  if ($did == 9) {
    if ( $did(away,8).text != $null ) {
      set %jonsaway.awaymessage $did(away,8).text
      did -t away 10
      did -b away 9
      did -e away 10
      nick %jonsaway.awaynick
      amsg 13I am now away: %jonsaway.awaymessage $+ .
      away %jonsaway.awaymessage
      .timers off
    }
    else {
      echo -a You didn't enter an away message!
    }
  }
  if ($did == 10 ) {
    amsg 13I am now back from: %jonsaway.awaymessage $+ .
    nick %jonsaway.regnick
    away
    did -b away 10
    did -e away 9
  }
}
on *:INPUT:#: {
  if ($away == $false) {
    .timer100 1 2400 /nick %jonsaway.awaynick
    .timer101 1 2400 /away Auto-away after 40 minutes of idling.
    .timer102 1 2400 /set %jonsaway.awaymessage Auto-away after 40 minutes of idling
    .timer103 1 2400 /amsg 13I am now away: Auto-away after 40 minutes of idling $+ .
  }
}