Not working Adding a Salary Filter to the Job Search Form (advanced)

you can check same issue have some other users:
https://stackoverflow.com/questions/31855607/wp-job-manager-custom-filter
https://gist.github.com/mikejolley/68f46aa2f2a38fa59090#file-gistfile1-php

truetester the code is fine. If you paste it in wrong, or leave in <?php if you have one already, that will break it ??