title: Targeting a html element but only on specified page
body: <p>I'm using a shop CMS that allows me to apply a side menu for all product categories, let's call them Necklaces and Rings, that CMS also has an option to add "New" and "Promotions" to that side menu globally, however what I cannot do is specify where I want these "New" and "promotions" to be. For example I want them to be displayed in Rings category but not in Necklaces.</p>
  
  <p>This is a rough sketch how the website is made:</p>
  
  <pre><code>   &lt;div class="menu" id="side_menu"&gt;
    &lt;ul class="standard"&gt;
       &lt;li id="category_newstuff"&gt;&lt;a href="/pl/c/Bizuteria/13" title="New"&gt;New&lt;/a&gt;&lt;/li&gt;
       &lt;li id="category_14"&gt;&lt;a href="/pl/c/Collection/14" title="Collection1"&gt;Collection1&lt;/a&gt;
       &lt;li id="category_14"&gt;&lt;a href="/pl/c/Collection/14" title="Collection2"&gt;Collection2&lt;/a&gt;
       &lt;li id="category_14"&gt;&lt;a href="/pl/c/Collection/14" title="Collection3"&gt;Collection3&lt;/a&gt;
       &lt;li id="category_14"&gt;&lt;a href="/pl/c/Collection/14" title="Collection4"&gt;Collection4&lt;/a&gt;
       &lt;li id="category_promotions"&gt;&lt;a href="/pl/promotions" title="Promotions" class="promo"&gt;Promotions&lt;/a&gt;&lt;/li&gt; 
  &lt;/div&gt;
  </code></pre>
  
  <p>What I want to achieve:</p>
  
  <p>If the page is: rings.html then find "li id="category_newstuff" and apply "style="display"none"></p>
  
  <p>I'm sorry if this is all gibberish lol.</p>