idhttp如何发送soap消息

大家好：
    我想通过idhttp控件发送如下消息，具体代码应该怎么写呢？POST /soap?class=GZL3 HTTP/1.1
Content-Type: text/xml; charset="utf-8"
Host: 138.120.79.172 (Note: this is the ATC IP Address)
SOAPAction:  (Note: no value for this field)<Envelope >
   <Body>
<DTIFault>
   <FaultStatus>1</FaultStatus>
   <FaultCode>2</FaultCode>
</DTIFault>
   </Body>
</Envelope>