If you don’t wish to use jQuery, there are a couple of simple functions you could use, like cloneNode(), createElement() and appendChild(). Here is a simple demonstration that appends a row to the end of the table using either the clone or create method. Tested in IE8 and FF3.5.
<html>
<head>
<script type="text/javascript">
function cloneRow() {
var row = document.getElementById("rowToClone"); // find row to copy
var table = document.getElementById("tableToModify"); // find table to append to
var clone = row.cloneNode(true); // copy children too
clone.id = "newID"; // change id or other attributes/contents
table.appendChild(clone); // add new row to end of table
}
function createRow() {
var row = document.createElement('tr'); // create row node
var col = document.createElement('td'); // create column node
var col2 = document.createElement('td'); // create second column node
row.appendChild(col); // append first column to row
row.appendChild(col2); // append second column to row
col.innerHTML = "qwe"; // put data in first column
col2.innerHTML = "rty"; // put data in second column
var table = document.getElementById("tableToModify"); // find table to append to
table.appendChild(row); // append row to table
}
</script>
</head>
<body>
<input type="button" onclick="cloneRow()" value="Clone Row" />
<input type="button" onclick="createRow()" value="Create Row" />
<table>
<tbody id="tableToModify">
<tr id="rowToClone">
<td>foo</td>
<td>bar</td>
</tr>
</tbody>
</table>
</body>
</html>