Tryit Editor v2.7

Edit This Code:

<!DOCTYPE html>
<html>
<body>

<p id="Demo">This is paragraph 1.</p>
<p id="demo">This is paragraph 2.</p>

<script>
  // Only paragraph 2 will be overwritten
  document.getElementById("demo").innerHTML = "HELLO.";
</script>

</body>
</html>