content: (*
  The rotate command takes a positive integer as the value for the to angle parameter. 
  To convert a negative rotation angle, such as -90 to a positive value, add 360: -90 + 360 = 270 
  *)
  set this_file to choose file without invisibles
  try
  	tell application "Image Events"
  		launch
  		-- open the image file
  		set this_image to open this_file
  		-- perform action
  		rotate this_image to angle 270
  		-- save the changes
  		save this_image with icon
  		-- purge the open image data
  		close this_image
  	end tell
  on error error_message
  	display dialog error_message
  end try