title: How to get the SessionID from soap:header?
body: <p>I got a soap xml response and I need the SessionID. I tried to use SimpleXml_load_string but got a empty object back. Has anybody any idea how to get the SessionID?</p>
  
  <p>This is the xml response:</p>
  
  <pre><code>&lt;?xml version="1.0" encoding="utf-8"?&gt;
  &lt;soap:Envelope xmlns:soap="http://schemas.xmlsoap.org/soap/envelope/" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema"&gt;
  &lt;soap:Header&gt;
      &lt;Header xmlns="http://www.twinfield.com/"&gt;
          &lt;SessionID&gt;ca363c52-c12f-4988-b06a-e0c41788e254&lt;/SessionID&gt;
      &lt;/Header&gt;
  &lt;/soap:Header&gt;
  &lt;soap:Body&gt;
      &lt;LogonResponse xmlns="http://www.twinfield.com/"&gt;
          &lt;LogonResult&gt;Ok&lt;/LogonResult&gt;
          &lt;nextAction&gt;None&lt;/nextAction&gt;
          &lt;cluster&gt;https://c3.twinfield.com&lt;/cluster&gt;
      &lt;/LogonResponse&gt;
  &lt;/soap:Body&gt;
  &lt;/soap:Envelope&gt;
  </code></pre>