;;; @ MIME entity
 ;;;
 
-(defun mime-entity-fetch-field (entity field-name)
+(defun mime-fetch-field (field-name &optional entity)
   (or (symbolp field-name)
       (setq field-name (intern (capitalize (capitalize field-name)))))
+  (or entity
+      (setq entity mime-message-structure))
   (let* ((header (mime-entity-original-header entity))
         (field-body (cdr (assq field-name header))))
     (or field-body
            )
          field-body))))
 
-(defun mime-entity-read-field (entity field-name)
+(defun mime-read-field (field-name &optional entity)
   (or (symbolp field-name)
       (setq field-name (capitalize (capitalize field-name))))
+  (or entity
+      (setq entity mime-message-structure))
   (cond ((eq field-name 'Content-Type)
         (mime-entity-content-type entity)
         )
         (let* ((header (mime-entity-parsed-header entity))
                (field (cdr (assq field-name header))))
           (or field
-              (let ((field-body (mime-entity-fetch-field entity field-name)))
+              (let ((field-body (mime-fetch-field field-name entity)))
                 (when field-body
                   (cond ((memq field-name '(From Resent-From
                                             To Resent-To