Javascript innerHTML() method
<html>
<head>
<title>Append a new row in table</title>
</head>
<body>
<h1>Append a new row in table</h1>
<table id="tb">
<tr>
<th>Table heading1</th>
<th>Table heading2</th>
</tr>
<tr>
<td>Table docuemnt1</td>
<td>Table docuemnt2</td>
</tr>
</table>
<br>
<button onclick="app()">Append new row</button>
<script>
function app() {
var x = document.getElementById('tb');
// get table data
var d = x.innerHTML;
x.innerHTML=d+'<tr><td>Table docuemnt1</td><td>Table docuemnt2</td></tr>';
}
</script>
</body>
</html>