[jQuery] nth-child(n) not working for me - I didn't see my previous post

[jQuery] nth-child(n) not working for me - I didn't see my previous post


I switch between var n = 2; nth-child(n) and nth-child(2) and get
different behavior.
Any suggestions/work arounds?
Thanks!
Here is the code:
<html>
<head>
<title>nth child</title>
<script type="text/javascript" src="jquery.js"></script>
<script type="text/javascript">
//Add input box for each column
$(function(){
     var n = 2;
//     $("#filterTable tbody tr td:nth-child(2)").each(function(){
     $("#filterTable tbody tr td:nth-child(n)").each(function(){
         $(this).append("this row");
     });
});
</script>
</head>
<body>
<table id="filterTable" width="580" border=1>
<thead>
<tr>
<th>Number</th>
<th>Letter</th>
<th>More</th>
</tr>
</thead>
<tbody>
<tr>
<td>1</td>
<td>A</td>
<td>A</td>
</tr>
<tr>
<td>2</td>
<td>A</td>
<td>B</td>
</tr>
<tr>
<td>3</td>
<td>B</td>
<td>3</td>
</tr>
<tr>
<td>4</td>
<td>B</td>
<td>D</td>
</tr>
</tbody>
</table>
</body>
</html>