Select process drop down in Post process UI is not updated after adding a new process

I created a new post process allownegative.php that just does the opposite of the existing allowpositive.php. I created this file with the same permissions as allowpositive.php on my raspberry pi /opt/emoncms/modules/postprocess/processes. However even after restarting my raspberry pi it still does not show in the webui for post process. I ran /opt/emoncms/modules/postprocess/ and after an initial error for misspelling the function name it shows no errors.
Is there another file i have to update to get it to appear as a valid process?

Found the solution.
The postprocess_controller.php also needs to be edited to populate the list in the webui.

If you are so inclined, can you submit this via GitHub? If you found it useful, someone else will.

Note, your updates will not work now as git will detect the difference in the files.