force download with header()

i was reading about php.net looking for a way to force a download of a txt file, rather than the browser displaying the file. i ran into header() that seems to be able to accomplish it... but seeing as i'm very much a newbie at php, i can't seem to make this work if the file i want to download is nfo/60/ind.txt how would i impliment this: <?php // We'll be outputting a PDF header("Content-type: application/pdf"); // It will be called downloaded.pdf header("Content-Disposition: attachment; filename=downloaded.pdf"); // The PDF source is in original.pdf readfile('original.pdf'); ?>