This is an example of a site specific add-on created specifically for a certain website.
This site specific plugin adds a formatting function for a custom field created by a third party plugin. In this case the field is called ‘teachers-website’.
The formatting function therefore must be called:
ausers_format_teachers_website($v, $u)
This example includes target=”_blank” as that was requested. However please read what various institutions advise about opening new windows on links: http://webdesign.anmari.com/2820/dont-force-open-new-windows/
Instructions on how to create your own formatting function are here: https://wpusersplugin.com/2645/format-any-field-any-way-you-wish/
amr_format_extra_fields (zip file)