Untitled

<html>
<head>
  <title>
  :: Latihan Javascript ::
  </title>
</head>
<body>
<h1>Simple Calculator</h1>
<form>
<table border="1" cellpadding="4px" cellspacing="6px">
  <tr>
   <td colspan="4" align="center"> <input type="text" id="angka" value="" > </td>
  </tr
  <tr>
    <td align="center"><input type="button" value="1" onclick="pencet(this)"/></td>
    <td align="center"><input type="button" value="2" onclick="pencet(this)"/></td>
    <td align="center"><input type="button" value="3" onclick="pencet(this)"/></td>
    <td align="center"><input type="button" value="+" onclick="pencet(this)"/></td>
  </tr>
  <tr>
    <td align="center"><input type="button" value="4" onclick="pencet(this)"/></td>
    <td align="center"><input type="button" value="5" onclick="pencet(this)"/></td>
    <td align="center"><input type="button" value="6" onclick="pencet(this)"/></td>
    <td align="center"><input type="button" value="-" onclick="pencet(this)"/></td>
  </tr>
  <tr>
    <td align="center"><input type="button" value="7" onclick="pencet(this)"/></td>
    <td align="center"><input type="button" value="8" onclick="pencet(this)"/></td>
    <td align="center"><input type="button" value="9" onclick="pencet(this)"/></td>
    <td align="center"><input type="button" value="*" onclick="pencet(this)"/></td>
  </tr>
  <tr>
    <td align="center"><input type="button" value="0" onclick="pencet(this)"/></td>
    <td align="center"><input type="reset"  value="C" id="clear" /></td>
    <td align="center"><input type="button" value="." onclick="pencet(this)"/></td>
    <td align="center"><input type="button" value="/" onclick="pencet(this)"/></td>
  </tr>
  <tr>
   <td colspan=4>
      <input type=button value="=" onclick="result()" >
   </td>
  </tr>
</table>
</form>
<style type="text/css">
  #angka{
    font-size: 30pt;
    text-align: right;
    width: 220px;
  }
  input[type="button"], input[type="reset"]{
    width: 100%;
  }
</style>
<script>
  var angka = '';
  var hasil = 0;
  function pencet(e){
    if (hasil > 0 || document.getElementById('angka').value == 0){
      document.getElementById('angka').value = '';
      hasil = 0;
    }
    angka = e.value;
    document.getElementById('angka').value += e.value ;
    angka += angka;
  }

  function result(){
    angka2 = document.getElementById('angka').value;
    hasil = eval(angka2);
    if (hasil !== undefined) {
      document.getElementById('angka').value = hasil;
    }
  }
</script>
</body>
</html>