Post XML til web Methods Server

Subject: Connecting to service by means of http post.

I have a service called TS_GetProdSpec reciding in the folder "ProdSpec.Services"

I have specified the following for the service:

- Namespace name: http:\\mes-srv2:5555\
- Local name: TS_GetProdSpec

I'm writing a VB Client using the MSXML.XMLHTTPRequest to transmit an XML Document to the service.

Questions:

1: What is the syntax for invoking this service over HTTP?

2: How do I supply username and password?