请问如何得到，一个表格中某个单元的左上角坐标？

[muly]

[cpplus]

<body>
<div><table border="1">
<tr>
<td> 
</td>
<td id=mxh> 
</td>
</tr>
</table>
<input onclick="alert(document.all.mxh.offsetLeft+'\n'+document.all.mxh.offsetTop)" value="位置" type=button>
</body>

[whiteclude]

<script>
document.onclick = clicks;
function clicks() {
var srcIndex = event.srcElement.sourceIndex;
if ( document.all[srcIndex].tag == 't') {
alert(document.all[srcIndex].offsetTop)
}

}
</script>
<table border='1'>
<tr>
<td tag='t'>a</td>
<td tag='t'>b</td>
<td tag='t'>c</td>
</tr>
<tr>
<td tag='t'>d</td>
<td tag='t'>e</td>
<td tag='t'>f</td>
</tr>
<tr>
<td tag='t'>g</td>
<td tag='t'>h</td>
<td tag='t'>i</td>
</tr>
</table>

[vincentmax]

偶来晚了...............