Renamed and refactored validation function, returned values instead of echo
Created and tested internal-functions.php

Creates function to check if a variable is set or empty and displays
the variable name. Runs tests in comments. Serializes and unserializes
an array.
Changed check of isset to empty on $something

Also output string saying $something is EMPTY
Included both isset and empty checks on $something
Reverted to only checking isset on $something
Unset $nothing before conditionals

Used unset($nothing) to unset $nothing before conditionals. $nothing is
still read as empty.