title: Check string and only wrap words NOT already wrapped?
body: <p>I hve the following HTML string: </p>
  
  <p><code>&lt;span class="class1"&gt;Hello&lt;/span&gt; my &lt;span class="class1"&gt;name&lt;/span&gt; is Mads.</code></p>
  
  <p>Is it possible to detect the words 'my', 'is' and 'Mads' and wrap those words in a string who is not already part of a span tag?</p>
  
  <p>So it becomes</p>
  
  <p><code>&lt;span class="class1"&gt;Hello&lt;/span&gt; &lt;span class="class1"&gt;my&lt;/span&gt; &lt;span class="class1"&gt;name&lt;/span&gt; &lt;span class="class1"&gt;is&lt;/span&gt; &lt;span class="class1"&gt;Mads.&lt;/span&gt;</code></p>
  
  <p>Thanks in advance.</p>