title: Undeclared prefix while loading SOAP xml
body: <p>I've received documentation from a client to use the below SOAP request. I've never worked with SOAP before and I'm using the solution listed in this question: <a href="https://stackoverflow.com/questions/4791794/c-sharp-client-send-soap-request-and-get-results">Client to send SOAP request and received response</a></p>
  
  <p>However, when <code>soapEnvelop.LoadXml</code> is run I get: <code>'head' is an undeclared prefix. Line 5, position 39.</code></p>
  
  <p>Here is the SOAP xml I received from my client:</p>
  
  <pre><code>&lt;soap:Envelope xmlns:xsi='http://www.w3.org/2001/XMLSchema-instance'
                 xmlns:xsd='http://www.w3.org/2001/XMLSchema'
                 xmlns:soap='http://schemas.xmlsoap.org/soap/envelope/'&gt;
      &lt;soap:Header&gt;
          &lt;head:CustomCredentials&gt;
              &lt;head:UserName&gt;Username&lt;/head:UserName&gt;
              &lt;head:Password&gt;Password&lt;/head:Password&gt;
              &lt;head:Source&gt;Code&lt;/head:Source&gt;
              &lt;head:CurrentCulture&gt;en-CA&lt;/head:CurrentCulture&gt;
          &lt;/head:CustomCredentials&gt;
      &lt;/soap:Header&gt;
      &lt;soap:Body&gt;
          &lt;WebServiceMethodName xmlns='Web Service Namespace' /&gt;                                        
      &lt;/soap:Body&gt;
  &lt;/soap:Envelope&gt;
  </code></pre>
  
  <p>I'm not entierly sure what to do here. From googling I believe that the element head just doesn't exist in the namespace.</p>