What is the role of the SOAPAction header?

[Joshua . White]

All,

I have a soap 1.1 client that I am trying to use with axis 1.3.  It appears that it is not sending the appropriate SOAPAction header.  What does this header do and why is it required?

Regards,

Joshua

*************************************************************************
This communication, including attachments, is
for the exclusive use of addressee and may contain proprietary,
confidential and/or privileged information. If you are not the intended
recipient, any use, copying, disclosure, dissemination or distribution is
strictly prohibited. If you are not the intended recipient, please notify
the sender immediately by return e-mail, delete this communication and
destroy all copies.
*************************************************************************