Why do you require:
WHERE DATE_ADDED
>= CURDATE()
First: the date added will not be more or the same as curdate(), which drops out the rest of your query.
Furthermore, you require them to be less then 15 days old, which is enough of a limit?
Anyway.. I would personally do this at php output level, unless you ONLY want to display those which are new.. (Because you will now run two queries: First finding those which are new, second findiing all relevant records, and then you cross match them. Sounds like a query too many to me, not to mention memory usage)
Otherwise:
-Select all records which you want to display
- As you loop through the records to display them, you check whether the date it less then 15 days old, and echo out 'new', or something, else not.
Just a thought