PHP: force browser download file

php_force_brower_download

			  header("Pragma: public");
  			header("Expires: 0"); 
  			header("Pragma: no-cache"); 
  			header("Cache-Control: no-store, no-cache, must-revalidate, post-check=0, pre-check=0");  
  			header("Content-Type: application/force-download"); 
  			header("Content-Type: application/octet-stream");
  			header("Content-Type: application/download");
  			header('Content-disposition: attachment; filename=' . '1006_3d-HK-Flag.png');
  			header("Content-Transfer-Encoding: binary");
  			header('Content-Length: ' . filesize(WWW_ROOT.'/feedback_files/1006_3d-HK-Flag.png'));
  			@readfile(WWW_ROOT.'/feedback_files/1006_3d-HK-Flag.png');