title: How to use if condition to hide element in Smarty template (TYPO3)?
body: <p>TYPO3 website is using TYPO3 extension of Smarty.
  In one existing template called header.tpl I have this code:</p>
  
  <pre><code>&lt;div class="header"&gt;
  ...
  &lt;/div&gt;
  &lt;div class="nav"&gt;
  ...
  &lt;/div&gt;
  </code></pre>
  
  <p>Is there some way to hide div element with the class "nav" using if condition? This header.tpl is used on every page, but I want to achieve that only on page with id=3 (in TYPO3) the navigation part will be hidden.</p>
  
  <p>For example:</p>
  
  <pre><code>&lt;div class="header"&gt;
  ...
  &lt;/div&gt;
  {if (???) }
  &lt;div class="nav"&gt;
  ...
  &lt;/div&gt;
  {/if}
  </code></pre>
  
  <p>Thank you very much for your help.</p>