Javascript window.alert output example

            <!DOCTYPE html>
<html>
<body>

    <h1>webthestuff</h1>
    <h2>Javascript Output</h2>
    <p>Click button to displaying the output using window.alert() </p>
    <button type="button" onclick="functionName()">Click Me!</button>

    <script>
        function functionName(){
            window.alert(10 + 10);
        }
    </script>

</body>
</html>
        

            
        