I have seen many away scipts but non that I like to use. I have messed around with other away scripts but I feel this is easier to use.
It just goes in your remotes. You need to edit it though. Where there is NAME put your mIRC nickname. To use it right click the channel menu and select a reason. You can add your own reasons to the script. Follow the same format and remember to change the suffix. If you dont want to save it click reason and it will rember it for that one time.

Any problems, I can be found on #dvasquadron

menu channel { 
  .away 
  ..Bbl    : set %away.reason I'll should be back later  | set %away.suffix Bbl | $set_away 
  ..Brb    : set %away.reason I'll be right back  | set %away.suffix Brb | $set_away 
  ..Na     : set %away.reason I'm not available at this time. | set %away.suffix Na | $set_away 
  ..Work   : set %away.reason I'm working at the moment | set %away.suffix Work | $set_away 
} 

alias set_away { 
  ame changed to $+(NAME_,%away.suffix) $+    - %away.reason $+ 
  nick $+(NAME_,%away.suffix) 
  away %away.reason 
} 

menu channel {
  .away
  ..Reason:/nowaway
  ..Back:/nowback
}

alias nowaway {
  /set %away $$?="Enter away reason here" 
  /away %away 
   /nick $+(NAME_,%away)
}

alias nowback {
  /away
  /ame is now back
  /unset %away
  /nick $+(NAME)
}