Overwrite files and eliminate headers

Hi,

I am using the following recipe to save an incoming message to
a file:

:0:
* ^Subject: saveme
savedfile

I have two questions:
1. The file: savedfile contains not only message text but also
the email headers, how can I eliminate all the headers so Procmail
only saves the message body.
2. When a new message arrives, the new message is appended to
the exiting savedfile. How can setup the recipe, so the new
message will overwrite the exiting savedfile.

Thanks in advance.

JZ