text: function encodeAndDecodeMessages() {
    let encodeTextAreaElement = document.getElementsByTagName('textarea')[0];
    let encodeBtnElement = document.getElementsByTagName('button')[0];
    let decodeTextAreaElement = document.getElementsByTagName('textarea')[1];
    let decodeBtnElement = document.getElementsByTagName('button')[1];
  
    if (encodeTextAreaElement === null || decodeTextAreaElement === null || encodeBtnElement === null || decodeBtnElement === null) {
      throw new Error('Something went wrong...');
    }
  
    encodeBtnElement.addEventListener('click', function() {
      let encodedMessage = '';
      for (let letter of encodeTextAreaElement.value) {
        encodedMessage += String.fromCharCode(letter.charCodeAt(0) + 1);
      }
      encodeTextAreaElement.value = '';
      decodeTextAreaElement.value = encodedMessage;
    });
  
    decodeBtnElement.addEventListener('click', function() {
      let decodedMessage = '';
      for (let letter of decodeTextAreaElement.value) {
        decodedMessage += String.fromCharCode(letter.charCodeAt(0) - 1);
      }
      decodeTextAreaElement.value = decodedMessage;
    });
  }
  