There is no function file in “wp-admin” folder, you do not need to edit that folder.
WordPress has Plugin api to do that,
http://codex.wordpress.org/Plugin_API/
Create a plugin and write function in your plugin file.
There is no function file in “wp-admin” folder, you do not need to edit that folder.
WordPress has Plugin api to do that,
http://codex.wordpress.org/Plugin_API/
Create a plugin and write function in your plugin file.