lesson 3

by anmol sandal

HTML

<html>

  <head>

    <script>
      function xxx() {

        var a = parseInt(document.getElementById('a1').value);
        var b = parseInt(document.getElementById('a2').value);
        var selector = document.getElementById('operator').value;
        var result;

        if (selector == '+') {
          result = a + b;
        }

        if (selector == '-') {
          result = a - b;
        }

        if (selector == '*') {
          result = a * b;
        }

        if (selector == '/') {
          result = a / b;
        }

        document.getElementById('result').innerHTML = result;
      }

    </script>
  </head>


  <body>

    <div>
      <input type="text" id="a1" value="" />
      <input type="text" id="a2" value="" />

      <select id="operator">
    <option value="+">add</option>
    <option value="-">sub</option>
    <option value="*">mul</option>
    <option value="/">div</option>
  </select>

      <p id="result"></p>
      <input type="submit" onclick="xxx()" value="calculate" />
    </div>
  </body>

</html>