js如何复制表格的某一行

[joecfan]

<table>
<tr>
<td>1.1</td>
<td>1.2</td>
<td>1.3</td>
</tr>
<tr id="tr1">
<td>a</td>
<td>b</td>
<td>c</td>
</tr>
<tr id="tr2">
<td>x</td>
<td>y</td>
<td>z</td>
</tr>
</table>
请问如何复制tr1，在后面也就是在tr2插入呢？效果如下
<table>
<tr>
<td>1.1</td>
<td>1.2</td>
<td>1.3</td>
</tr>
<tr id="tr1">
<td>a</td>
<td>b</td>
<td>c</td>
</tr>
<tr>
<td>a</td>
<td>b</td>
<td>c</td>
</tr>
<tr id="tr2">
<td>x</td>
<td>y</td>
<td>z</td>
</tr>
</table>

[豆虫]

var tbody = document.getElementById('table的id').tBodies[0];
var desTR = document.getElementById('t2');
var sourTR = document.getElementById('t1');
var newRow = tbody.insertRow();
newRow.innerHTML = sourTR.innerHTML;
tbody.insertBefore(newRow,desTR);

[joecfan]

我不想一个个cell的复制，想对tr1整行clone下

[BLUE_LG]

是用cloneNode()的意思？？？