How to add a JavaScript when a page is about to be printed

Try to print this document Tip: Keyboard shortcuts, such as Ctrl+P sets the page to print. Note: The onbeforeprint event is not supported in Safari and Opera.

index.html

Example: HTML

<!DOCTYPE html>
<html>
<body onbeforeprint="myFunction()">

<h1>Try to print this document</h1>
<p><b>Tip:</b> Keyboard shortcuts, such as Ctrl+P sets the page to print.</p>
<p><b>Note:</b> The onbeforeprint event is not supported in Safari and Opera.</p>

<script>
function myFunction() {
  alert("You are about to print this document!");
}
</script>

</body>
</html>

Output should be:

Type:	html
Category:	Web Tutorial
Sub Category:	HTML Window Event Attributes
Uploaded by:	Admin