headers-excel file-bad data

["blackwater dev" <blackwaterdev@xxxxxxxxx>]

Hello,

I have an excel file that I am generating.  If I copy over the generated
file and then open it in excel, it works fine, if I try to let the user
download it using the headers below, when I then open it excel complains
that it is an unrecognizable format and the info is garbled...any ideas???

Thanks!

    header('Pragma: public');
    header("Expires: Mon, 26 Jul 1997 05:00:00 GMT");                  //
Date in the past
    header('Last-Modified: '.gmdate('D, d M Y H:i:s') . ' GMT');
    header('Cache-Control: no-store, no-cache, must-revalidate');     //
HTTP/1.1
    header('Cache-Control: pre-check=0, post-check=0, max-age=0');    //
HTTP/1.1
    header ("Pragma: no-cache");
    header("Expires: 0");
    header('Content-Transfer-Encoding: none');
    header('Content-Type: application/vnd.ms-excel;');                 //
This should work for IE & Opera
    header("Content-type: application/x-msexcel");                    //
This should work for the rest
    header('Content-Disposition: attachment; filename="myfile.xls"');
    readfile("/tmp/myfile.xls");