Code and Output for script:

Code:

    <!DOCTYPE html>
    <html>
    <head>
      <title>Title of the document</title>
    </head>
    <body>
      <h1>App Genesis Soft Solutions pvt ltd</h1>
      <p id="demp"></p>
      <script>
      document.getElementById("demo").innerHTML="Hello JS";
      </script>
    </body>
    </html>

Output:

App Genesis Soft Solutions pvt ltd

Hello JS