COULD NOT RESEND HEADER..

Hi all. I try to make a page which checks the entire database and folder content, which able to delete all invalid data's in the folder and warns the user if an invalid data found in database. However I found the bug with 'header()' The codes below are not able to resend header if it's already sent, I need your advice: header("Cache-Control: no-cache, must-revalidate"); header("Expires: Fri, 04 June 1982 05:00:00 GMT"); // Date in the past header('Content-type: image/jpeg'); The error message: "could not resend header, header already sent in line.." And I also attach the quote of data for any one whom interested (to make it more advance), otherwise just leave it ! Best Regards ============BBC============ **o<0>o**