Tryit Editor v2.9

Edit This Code:
<!DOCTYPE html>
<html>
<head>
<style> 
table, th, td {
    border: 1px solid black;
}
</style>
</head>
<body>

<p>Click the "Try it" button to change the border-collapse property of the TABLE element:</p>

<button onclick="myFunction()">Try it</button>

<table id="myTABLE">
  <tr>
    <th>Name</th>
    <th>Age</th>
  </tr>
  <tr>
    <td>Emil</td>
    <td>9</td>
  </tr>
  <tr>
    <td>Tobias</td>
    <td>7</td>
  </tr>
  <tr>
    <td>Linus</td>
    <td>2</td>
  </tr>
</table>

<script>
function myFunction() {
    document.getElementById("myTABLE").style.borderCollapse = "collapse";
}
</script>

</body>
</html>