Demo of Accordion activate event using JQuery UI

Header 1 ( panel No. 0 )
Text about Header 1
Header 2 ( panel No. 1 )
Text about Header 2
Header 3
Text header 3
Header 4
Text about Header 4.
Tutorial on Accordion Animation DEMO: Accordion event beforeActivate

JQuery

<html>
<head>
<title></title>
<script src='https://code.jquery.com/jquery-3.1.1.min.js'></script>
<script src='https://code.jquery.com/ui/1.12.1/jquery-ui.min.js'></script>
<link href='https://code.jquery.com/ui/1.12.1/themes/cupertino/jquery-ui.css' rel='stylesheet'>
</head>
<body>
<div id='accordion' class='accordion'>
 <div class='header' id=hd1>Header 1 ( panel No. 0 )</div>
  <div class='content' id=cd1><span id=s1></span>
    Text about Header 1  
  </div>
 <div class='header' id=hd2>Header 2 ( panel No. 1 )</div>
  <div class='content' id=cd2>
    Text about Header 2    
  </div>
<div class='header' id=hd3>Header 3</div> 
  <div class='content' id=cd3>
    Text header 3
  </div>
<div class='header' id=hd4>Header 4</div>
  <div class='content' id=cd4>
    Text about Header 4.
   </div>
</div>
<div id=d1></div>
<script>
$(document).ready(function() {
//////////////////////////
$( '#accordion' ).accordion({
animate: 1000,
activate: function( event, ui ) {
$('#d1').html("newHeader : " + ui.newHeader.text() + " <br> newPanel : " + ui.newPanel.text() )
$('#d1').append(" <br><br> oldHeader : " + ui.oldHeader.text() + "<br> oldPanel : " + ui.oldPanel);
 }
});
/////////////////
})
</script>
</body>
</html>