File download Problem

[eluser]Star123[/eluser]
header('Content-type: application/jpg');
$name="s";
header("Content-Disposition: attachment; filename=$name");
readfile("http://localhost/nannyshare/uploads/01.01.03.07.10.57.0707800winter.jpg");

readfile("http://localhost/nannyshare/uploads/01.01.03.07.10.57.0707800winter.jpg");
does not work in codeigniter