content: tell application "Firefox Developer Edition"
      tell application "System Events" to tell application process "Firefox Developer Edition"
  		set previousWindowCount to (count of windows)
          tell menu 1 of menu bar item 3 of menu bar 1
          click (first menu item whose value of attribute "AXMenuItemCmdChar" is "N" and value of attribute "AXMenuItemCmdModifiers" is 0)
  		end tell
  		repeat while (count of windows) = previousWindowCount
  			delay 0.1
  		end repeat
      end tell
  set index of window (count of windows) to 1
  activate
  end tell
  