How to Execute a JavaScript when a <details> element is opened or closed - HTML ontoggle Attribute

Click on Arrow to Open the details System HTML Code.

index.html

Example: HTML

<!DOCTYPE html>
<html>
<body>

<p>Open the details.</p>

<details ontoggle="myFunction()">
<summary>Copyright 1999-2014.</summary>
<p> - by Refsnes Data. All Rights Reserved.</p>
<p>All content and graphics on this web site are the property of the company Refsnes Data.</p>
</details>

<script>
function myFunction() {
  alert("The ontoggle event occured");
}
</script>

</body>
</html>

Output should be:

Type:	html
Category:	Web Tutorial
Sub Category:	HTML Attribute
Uploaded by:	Admin