<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Anonymous Function</title>
    <script>
        // Assign an anonymous function to a variable
        var sayHello = function() {
            alert("Hello from an anonymous function!");
        };
    </script>
</head>
<body>
    <!-- Button element with an onclick event handler using the anonymous function -->
    <button onclick="sayHello()">Say Hello</button>
</body>
</html>