Tryit Editor v2.7

Edit This Code:
<!DOCTYPE html>
<html>
<body>

<p>Replace "Microsoft" with "W3Schools" in the paragraph below:</p>

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

<p id="demo">Please visit Microsoft!</p>

<script>
  function myFunction() {
    var str = document.getElementById("demo").innerHTML;
    var txt = str.replace("Microsoft", "W3Schools");
    document.getElementById("demo").innerHTML = txt;
  }
</script>

</body>
</html>