$ disposition = isImg ( $ attachmentpath ) ? 'inline' : 'attachment' ;
         $ db_charset == 'utf-8' && $ attdata [ 'filename' ] = convert_encoding ( 'utf-8' , 'gbk' , $ attdata [ 'filename' ] ) ;
         strpos ( $ _SERVER [ 'HTTP_USER_AGENT' ] , 'MSIE' ) !== FALSE && $ attdata [ 'filename' ] = urlencode ( $ attdata [ 'filename' ] ) ;
         header ( 'Cache-control: max-age=31536000' ) ;
         header ( 'Expires: ' . gmdate ( 'D, d M Y H:i:s' , $ timestamp + 31536000 ) . ' GMT' ) ;
         header ( 'Last-Modified: ' . gmdate ( 'D, d M Y H:i:s' , $ attdata [ 'uploaddate' ] ) . ' GMT' ) ;
         header ( 'Content-type: ' . $ attdata [ 'filetype' ] ) ;
         header ( 'Content-Encoding: none' ) ;
         header ( 'Content-Disposition: ' . $ disposition . '; filename=' . $ attdata [ 'filename' ] ) ;
         header ( 'Content-Length: ' . filesize ( $ attachmentpath ) ) ;
         header ( 'Content-Transfer-Encoding: binary' ) ;
         @ readfile ( $ attachmentpath ) ;