<html>
    <title>Reverse a string in javascript</title>
    <body>
        <center><br>
            <label>Enter Any String:</label>  <input type="text" id="str">
            <button type="button" id="btn" onclick="revString()">  Reverse String</button><br>
            <hr>
            <h2 style="color:green" id="orgString"></h2>
            <h2 style="color:green" id="revString"></h2>
        </center>
    </body>
    <script type="text/javascript">
      function revString() {
          let str = document.getElementById('str').value; 
          let revString = '';
          document.getElementById('orgString').innerHTML = 'Original String: '+str; 
          for (var i = str.length - 1; i >= 0; i--) {
            revString+= str[i];
          }
          document.getElementById('revString').innerHTML = 'Reverse String: '+revString; 
      }
    </script>
</html>