Require script to delete duplicates from two lists

Hello there - Looking for a piece of code (PHP preferred) which allows me to enter two lists into two form fields and show me ONLY the items unique to list 2 For example: List1 aaa bbb ccc ddd hhh List2 bbb zzz ddd eee After clicking submit I would return with the result: zzz eee To confirm: ONLY the keywords unique to LIST 2 are displayed as a result. Any keyword unique to List 1 or duplicated in both List1/2 are NOT shown as a result.