Edit script syntax - Toggle bluetooth according to power setting

Question

Using a MBPr13 on OSX ML 10.8.4, needing to toggle Bluetooth based on Power source. Found a dated script, but I'm not script savvy so hoping someone could help me edit it:
#! /bin/bash
PREVIOUS_SOURCE=$(pmset -g ps | perl -ne '/(w+) Power/ && print $1');
while [ 1 ]; do
  CURRENT_SOURCE=$(pmset -g ps | perl -ne '/(w+) Power/ && print $1');
  if [ $CURRENT_SOURCE != $PREVIOUS_SOURCE ]; then
    PREVIOUS_SOURCE=$CURRENT_SOURCE
    if [ $CURRENT_SOURCE = "AC" ]; then
      blueutil on
    else
      blueutil off
    fi
  fi
  sleep 5
done
When I compile in Apple Script Editor, I get "Expected expression but found unknown token" Syntax Error and the $ character is highlighted (as above).
Comments posted on the web page where I found this suggest that some of the "escapes on the word characters" have been stripped? Can anyone suggest how this could be edited to work?
Cheers, Sla

Answer 1

The previous script doesn't quite work properly, this one is better:
tell application "System Preferences"
  activate
          set the current pane to pane id "com.apple.preferences.bluetooth"
end tell
set _power to do shell script "pmset -g | grep AC"
set _power to last character of _power
if _power = "*" then
          tell application "System Events"
                         set _status to checkbox "On" of window "Bluetooth" of application process "System Preferences"
                         tell _status
                                        if not (its value as boolean) then click _status
                         end tell
          end tell
else
          tell application "System Events"
                         set _status to checkbox "On" of window "Bluetooth" of application process "System Preferences"
                         tell _status
                                        if (its value as boolean) then click _status
                         end tell
          end tell
end if
tell application "System Preferences" to quit