!brb command

how i can make like if says !brb then just says [NICK] Will Be Right Back! Reason: NONE

and if says !brb toilet then says [NICK] Will Be Right Back! Reason: toilet

if ($3 == !brb) { 
;$4-:Reason 
  if ($4- == $null) { 
    mta.text $1 $mta.nick($1,$2) will be right back! 
    } 
  else mta.text $1 $mta.nick($1,$2) will be right back - Reason: $4- 
} 
  

thx, but how i can also make !hi command like

!hi -> [NICK] Says Hello To Everyone!

!hi raz -> [NICK] Says Hello To Raziel!

I mean it wont say raz but it will say full name, how i can do that?

on *:SIGNAL:mta.command: { 
var %a = $iif($4,$iif($mta.nick($1,$4) != $null,$4,$gus.getid($1,$4)),$2) 
if ($3 == !hi) || ($3 == !hello) { 
;$4-:Reason 
  if ($4- == $null) { 
    mta.text $1 $mta.nick($1,$2) says hello to everyone! 
    } 
  else mta.text $1 $mta.nick($1,$2) says hello to $mta.nick($1,%a) 
} 

- or -

on *:SIGNAL:mta.command: { 
var %a = $iif($4,$iif($mta.nick($1,$4) != $null,$4,$gus.getid($1,$4)),$2) 
if ($3 == !hi) || ($3 == !hello) { 
;$4-:Reason 
  if ($4- == $null) { 
    mta.text $1 $mta.nick($1,$2) says hello to everyone! 
    } 
  else mta.pm $1 %a  $mta.nick($1,$2) says hello to you! 
} 

k, here's mine for both

on *:SIGNAL:mta.command:{ 
  if ($3 == !brb) mta.text $1 $mta.nick($1,$2) will be right back! $iif($4,Reason: $4-) 
  elseif ($3 == !hi) mta.text $1 $mta.nick($1,$2) says hello to $iif($mta.getid($1,$4),$mta.nick($1,$mta.getid($1,$4)),everyone) $+ ! 
} 
  

k, here's mine for both

on* :SIGNAL:mta.command:{ 
  if ($3 == !brb) mta.text $1 $mta.nick($1,$2) will be right back! $iif($4,Reason: $4-) 
  elseif ($3 == !hi) mta.text $1 $mta.nick($1,$2) says hello to $iif($mta.getid($1,$4),$mta.nick($1,$mta.getid($1,$4)),everyone) $+ ! 
} 
  

damn you