Converting data types

Hello, I have a variable which is of type "unsigned long" (note_id) which I'm trying to return back to the user in an array. I used add_index_long(return_value,i,note_id); but I get a value of 8566 when I should be getting 2176. Is there a function that I can use to convert the note_id to "long" which add_index_long() expects? Unfortunatly the function which I'm receiving note_id from make the type unsigned long, and that I can't change. Any suggestions would be greatly appreciated. Thanks, Brad Atkins