如何使用请求并使用xml和VB.net进行响应？

他们告诉我,请求应该是这样的：

request( 
p1 - loginInfo:UN|PASS|MP1
p2 - XMLTransactionInfo (below)
p3 - returnPointBalance:1
)

<transaction>
  <partnernum>000001</partnernum>
  <trxndate>2012-10->12T07:18:27</trxndate>
  <cardnum>1234567891234567</cardnum>
  <trxnamount>5.4</trxnamount>
  <trxnpoints>729</trxnpoints>
  <posnum>000-001</posnum>
  <contactidnum></contactidnum>
  <contactphone>357</contactphone>
  <trxnseqnum>12345612345612</trxnseqnum>
</transaction>

响应应该是这样的：

response(    
<?xml version="1.0" encoding="UTF-8"?> 
<transactionresponse xmlns="C:pathSth.earSth.war/xmlschema/TransactionResponse.rng">
  <sequencenum>123123121312</sequencenum> 
  <errorcode>0</errorcode> 
  <errormessage></errormessage> 
  <trxnnum>6399575</trxnnum> 
  <balancebefore>1942</balancebefore> 
  <balanceafter>1213</balanceafter> 
  <mpcontrib>729</mpcontrib> 
  <partnercontrib>0</partnercontrib> 
</transactionresponse>
)

他们还告诉我：“你可以使用这个URL获取WSDL：url1 ……”和“WS端点是：url2 ……”

到目前为止,我已成功完成以下任务：

Dim request As WebRequest = Nothing

  'Create a request for the URL.
  request =WebRequest.Create("URL1")

  'set the credentials.
  Dim credentials As NetworkCredential
  loginUser = "username"
  loginPass = "pass"
  credentials = New NetworkCredential(loginUser,loginPass,"MP1")
  request.Credentials = credentials

  'create the transaction xml
  request.ContentType = "text/xml"
  Dim transaction As XmlElement
  transaction = xml2.CreateElement("transaction")
  xml2.AppendChild(transaction)

  Dim partnernum As XmlElement
  partnernum = xml2.CreateElement("partnernum")
  partnernum.InnerText = "00001"
  transaction.AppendChild(partnernum)

  'and so on until i create the exact same xml as above...

然后我将XML文件打印到控制台进行目视检查,然后请求响应

'print to console
  xml2.Save(Console.Out)
  Dim response As WebResponse = request.GetResponse()
  Console.WriteLine(response.ToString())
  'write the response to a textbox
  responseText.Text = response.Headers.ToString()

文本框中的响应结果是

Content-Language: el-GR
Transfer-Encoding: chunked
Content-Type: text/xml
Date: Thu,13 Dec 2012 18:52:33
GMT Server: WebSphere Application Server/6.0

首先,我应该使用他们给我的2个网址中的哪一个？

其次,如何创建他们告诉我的请求以获得我想要的响应？

有没有一步一步的指导？

我正在使用VB.net,WinForms.
感谢您的时间.