title: Remove All html tag except one tag
body: <p>I have some code to remove all html tag but I want to remove all html but except <code>&lt;/td&gt;</code> and <code>&lt;/tr&gt;</code> tags.</p>
  
  <p>How can this be done?</p>
  
  <pre><code>public string HtmlStrip( string input)
  {
      input = Regex.Replace(input, "&lt;input&gt;(.|\n)*?&lt;/input&gt;", "*");
      input = Regex.Replace(input, @"&lt;xml&gt;(.|\n)*?&lt;/xml&gt;", "*"); // remove all &lt;xml&gt;&lt;/xml&gt; tags and anything inbetween.  
      return Regex.Replace(input, @"&lt;(.|\n)*?&gt;", "*"); // remove any tags but not there content "&lt;p&gt;bob&lt;span&gt; johnson&lt;/span&gt;&lt;/p&gt;" becomes "bob johnson"
  }
  </code></pre>