try
  set myvar to do shell script "defaults read com.apple.finder AppleShowAllFiles"
  if myvar is "FALSE" then
    do shell script "defaults write com.apple.finder AppleShowAllFiles TRUE"
    do shell script "killall Finder"
  else if myvar is equal to "TRUE" then
    do shell script "defaults write com.apple.finder AppleShowAllFiles FALSE"
    do shell script "killall Finder"
  else
    display dialog "Error"
  end if
on error
  display dialog "Would you like to hide files or show files?" buttons {"Show", "Hide"} default button "Hide"
  set myChoice to button returned of result
  if myChoice is "Show" then
    do shell script "defaults write com.apple.finder AppleShowAllFiles TRUE"
    do shell script "killall Finder"
  else if myChoice is "Hide" then
    do shell script "defaults write com.apple.finder AppleShowAllFiles FALSE"
    do shell script "killall Finder"
  else
    display dialog "Error"
  end if
end try