So 19130697
by Tushar Gupta
HTML
<table>
<tr>
<td>
<input type="text" name="data1" value="abc" />
</td>
<td>
<button type="button" onClick="addRow(this)">Add</button>
</td>
</tr>
</table>
JavaScript
function addRow(btn) {
var parentRow = btn.parentNode.parentNode;
var table = parentRow.parentNode;
var rowCount = table.rows.length;
var row = table.insertRow(rowCount);
var cell1 = row.insertCell(0);
var element1 = document.createElement("input");
element1.type = "text";
cell1.appendChild(element1);
var cell3 = row.insertCell(1);
}