title: OnLoad in body does not work with wordpress?
body: <p>Wordpress site, creating preloader for content div using Jquery and CSS, I found simple and great one here: <a href="https://www.w3schools.com/howto/tryit.asp?filename=tryhow_css_loader5" rel="nofollow noreferrer">https://www.w3schools.com/howto/tryit.asp?filename=tryhow_css_loader5</a></p>
  
  <pre><code>&lt;script type="text/javascript"&gt;
  jQuery(document).ready(function( $ ) {
  //A page can't be manipulated safely until the document is "ready."
  var myVar;
  
  function myFunction() {
    myVar = setTimeout(showPage, 3000);
  }
  
  function showPage() {
    document.getElementById("loader").style.display = "none";
    document.getElementById("content").style.display = "block";
  }
  });
  &lt;/script&gt;
  </code></pre>
  
  <pre><code>&lt;style type="text/css"&gt;
  #loader {
    position: absolute;
    left: 50%;
    top: 50%;
    z-index: 1;
    width: 150px;
    height: 150px;
    margin: -75px 0 0 -75px;
    border: 16px solid #f3f3f3;
    border-radius: 50%;
    border-top: 16px solid #3498db;
    width: 120px;
    height: 120px;
    -webkit-animation: spin 2s linear infinite;
    animation: spin 2s linear infinite;
  }
  
  @-webkit-keyframes spin {
    0% { -webkit-transform: rotate(0deg); }
    100% { -webkit-transform: rotate(360deg); }
  }
  
  @keyframes spin {
    0% { transform: rotate(0deg); }
    100% { transform: rotate(360deg); }
  }
  
  /* Add animation to "page content" */
  .animate-bottom {
    position: relative;
    -webkit-animation-name: animatebottom;
    -webkit-animation-duration: 1s;
    animation-name: animatebottom;
    animation-duration: 1s
  }
  
  @-webkit-keyframes animatebottom {
    from { bottom:-100px; opacity:0 } 
    to { bottom:0px; opacity:1 }
  }
  
  @keyframes animatebottom { 
    from{ bottom:-100px; opacity:0 } 
    to{ bottom:0; opacity:1 }
  }
  
  #content {
    display: none;
  }
  &lt;/style&gt;
  </code></pre>
  
  <pre><code>&lt;body onload="myFunction()" style="margin:0;"&gt;
  
  &lt;div id="loader"&gt;&lt;/div&gt;
  &lt;div id="content" class="site-content container clear"&gt;
  Preload this text.
  &lt;/div&gt;
  </code></pre>
  
  <p>And the error is:
  <code>myFunction is not defined at onload ((index):420)</code></p>
  
  <p>Is there a workaround for WordPress or maybe other, simple way of adding preloader for particular div id?</p>