Simply Monthly Bandwidth Report (Single Interface)

I have searched through the forums and have found some scripts which will do somewhat what I want but I haven’t been able to adapt them for my purpose (Referring to “http://wiki.mikrotik.com/wiki/Automated_Usage_Script_without_usermanager”). What I am looking for is a script which will do the following:

  1. Generate a simple report with the total bytes (GB Format) inbound on ether1 (Named WAN) and outbound on ether1
  2. Send the report via email (Email already setup and working from routerboard) at the end of the month and reset the values.
  3. Allow me to manually run a report at anytime throughout the month without resetting the values.

I also have firewall passthrough filters both inbound and outbound on the interface in order to get a total but I want something more automated.

Any help is appreciated.