#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) != '(' \
&& (c) != ')' && (c) != '<' && (c) != '>' \