#define ENCODING_FIELD "Content-Transfer-Encoding"
#define ID_FIELD "Content-ID"
#define DESCR_FIELD "Content-Description"
+#define DISPO_FIELD "Content-Disposition"
#define MD5_FIELD "Content-MD5"
#define isatom(c) (!isspace (c) && !iscntrl (c) && (c) != '(' \