How to replace the word in the paragraph using javascript?

Html Page:

<p id="demo">Visit Microsoft!</p>

<button onclick="myFunction()">Try it</button>

Javascript page:

<script>

    function myFunction() {

        var str = document.getElementById("demo").innerHTML;

        var res = str.replace("Microsoft", "InfoItbook");

        document.getElementById("demo").innerHTML = res;

    }

</script>

Output:

Visit InfoItbook