title: special characters in XML file
body: <p>I am using an XML file in my application. I want to write my query string into the XML file and then read it from the application side. My query is like that:</p>
  
  <pre><code>select * from employee
  where salary &lt; 10000
  </code></pre>
  
  <p>I faced this problem: when I write this character <code>'&lt;'</code> I got an error. How can I use it in my XML? Thanks.</p>