How to search the word and display the position in given paragraph using javascript?

Html Page:

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

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

Javascript page:

<script>

    function myFunction() {

        var str = "Visit W3Schools!";

        var n = str.search("W3Schools");

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

    }

</script>

Output:

6