How to display a string as a hyperlink using javascript?

Html page:

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

<p id="P1"></p>

Javascript page:

<script>

    function myFunction() {

        var str = "Free Web Building Tutorials!";

        var result = str.link("http://www.info-it-book.blogspot.com");

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

    }

</script>

output:

Free Web BuildingTutorials!