iMacro Code to Delete Facebook Messages

Here is the iMacro code that worked pretty quickly for deleting all my archived Facebook messages and chats. Just copy and paste the code below into an iMacro file and save with your preferred name. Then (whilst logged into Facebook) double click the file in iMacros to run the script.
Firstly if you do not have it the iMacros plugin for Firefox can be found through a link on this page
Then add the following code into an iMacro file (.iim) and save with a new name. Please check the build number in one of your exisiting sample iMacro files as if you have a different build you may have to change this.