javascript让TR添加/删除TD

条件:
TR的ID为 tr01

代码:
<script language="javascript">
function add( text ){
   var oTr = document.all("tr01");
   var oTd = oTr.insertCell();
   oTd.innerText = text;
}

function del(){
   var oTr = document.all("tr01");
   oTr.deleteCell(i);   //删除第i个单元格
}

</script>