title: How to search only in post title - wp_query
body: <p>I added a text field to the posts filter form and I use s= parameter to make the search work. But how to search only in the title of the post (not in the content)?</p>
  
  <p>HTML:</p>
  
  <pre><code>&lt;input type="text" name="search" placeholder="Search..." value=""&gt;
  &lt;button&gt;Filter&lt;/button&gt;
  </code></pre>
  
  <p>PHP:</p>
  
  <pre><code>    $args = array(
          'post_type' =&gt; $_POST['posttype'], 
          'orderby' =&gt; $_POST['orderby'], 
          'order' =&gt; $_POST['order'],
          's' =&gt; $_POST['search']
      );
  </code></pre>