Writing SOAP Headers

[Tony Simon]

I'm using Visual Basic and Microsoft SOAP Toolkit v3.0.

I need to use the low level API since the server I'm attaching to does
not support WSDL, and I need to send sessionID information in the SOAP
header but I can't get my code to work.

I can write a SOAP message just fine following the examples in the
toolkit, but when I try to access the header with methods such as:
Serializer.StartHeader, I get a Run Time Error stating that the
StartHeader method of ISoapSerializer failed.

All the examples in the documentation show high level API examples for
writing out the Headers. The examples show writing the read/write
methods for IHeaderHandler, instantiating this object and setting it to
the SoapClient30.HeaderHandler. But SoapClient30 is the high level API,
not the low level API. I need a way to write out the header from
SoapSerializer.

As a side question, what is ISoapSerializer? Is it the same as
SoapSerializer30?

Thanks,
Tony

[Tony Simon]

Found the problem. The low level API works fine as long as everything
is done in the right ordered. Serializer.StartHeader and all other
header elements have to be the first element set after
Serializer.StartEvelop.