Smart File Download

[mbusi]

I've downloaded the script ok! but it's just not working i'm getting this error message:

    (File does not exist. Make sure you specified correct file name)

i don't know how to fix it..!
i was thinking that maybe the problem lies in the statment (define('BASE_DIR','test.co.za/Downloadmp3/')) and ($file_path = ''), i'm not sure as to what to put in the define satement and $file_path.
Please help!