I can not upload files SWF

I can not upload files .SWF to the library. I get error: Permission denied.

I found the code on the Internet (must be put in functions.php):
add_filter(‘upload_mimes’, ‘mqw_mas_extensiones’);
function mqw_mas_extensiones ( $existing_mimes=array() ) {
// Agregamos nuevas extensiones al array al lado de su MIME type:
$existing_mimes[‘swf’] = ‘application/x-shockwave-flash‘;
$existing_mimes[‘mp3’] = ‘audio/mpeg3‘;
//Agregamos las que necesitemos y luego retornamos el array
return $existing_mimes;
}

BUT DOES NOT WORK