title: Regex for detecting a query string
body: <p>I'm trying to use regex for testing a URL. </p>
  
  <ul>
  <li><p>accepted cases: </p>
  
  <pre><code>www.mystite.com/whatever/?bla=dfgsd&amp;page=test 
  www.mystite.com/whatever/?bla=dfgsd&amp;page=test&amp;
  www.mystite.com/whatever/?bla=dfgsd&amp;page=test&amp;hello=bla 
  www.mystite.com/whatever/?page=test&amp;hello=bla
  </code></pre></li>
  <li><p>rejected:</p>
  
  <pre><code>www.mystite.com/whatever/?hello=bla&amp;page=testfff 
  www.mystite.com/whatever/?page=testfff&amp;hello=bla - NOT good
  </code></pre></li>
  </ul>
  
  <p>because misses <strong><code>&amp;page=test&amp;</code></strong>, <strong><code>page=test&amp;</code></strong> or <strong><code>&amp;page=test</code></strong></p>
  
  <p>That's what I tried, and it doesn't work:</p>
  
  <pre><code>([^&amp;amp;]+)([page=test])([^&amp;amp;]+)
  </code></pre>
  
  <p>You can ignore the domain and sub folder, what I'm trying to check is only after the question mark</p>