Real-Time Editor

<!DOCTYPE html>
      <html>
      <head>
          <title>Temperature Converter</title>
      </head>
      <body>
          <h1>Temperature Converter</h1>
          <form>
              <label for="value">Value:</label>
              <input type="number" id="value" name="value"><br><br>
              <label for="from">From:</label>
              <select id="from" name="from">
                  <option value="celsius">Celsius</option>
                  <option value="fahrenheit">Fahrenheit</option>
                  <option value="kelvin">Kelvin</option>
              </select><br><br>
              <label for="to">To:</label>
              <select id="to" name="to">
                  <option value="celsius">Celsius</option>
                  <option value="fahrenheit">Fahrenheit</option>
                  <option value="kelvin">Kelvin</option>
              </select><br><br>
              <input type="button" value="Convert" onclick="convert()"><br><br>
              <label for="result">Result:</label>
              <input type="text" id="result" name="result"><br><br>
          </form>
      
          <script>
              function convert() {
                  var value = parseFloat(document.getElementById("value").value);
                  var from = document.getElementById("from").value;
                  var to = document.getElementById("to").value;
      
                  var result;
      
                  switch(from) {
                      case "celsius":
                          switch(to) {
                              case "celsius":
                                  result = value;
                                  break;
                              case "fahrenheit":
                                  result = (value * 1.8) + 32;
                                  break;
                              case "kelvin":
                                  result = value + 273.15;
                                  break;
                          }
                          break;
                      case "fahrenheit":
                          switch(to) {
                              case "celsius":
                                  result = (value - 32) / 1.8;
                                  break;
                              case "fahrenheit":
                                  result = value;
                                  break;
                              case "kelvin":
                                  result = (value + 459.67) / 1.8;
                                  break;
                          }
                          break;
                      case "kelvin":
                          switch(to) {
                              case "celsius":
                                  result = value - 273.15;
                                  break;
                              case "fahrenheit":
                                  result = (value * 1.8) - 459.67;
                                  break;
                              case "kelvin":
                                  result = value;
                                  break;
                          }
                          break;
                  }
      
                  document.getElementById("result").value = result.toFixed(2);
              }
          </script>
      </body>
      </html>