Js点击内容出现文本输入框

[Tony]

<script>
function Modify(id) {
  var content = id.innerHTML;
    id.onclick = null;
  var tdId = id.id;
  document.getElementById(tdId).innerHTML = "<input name=n" + tdId + " value=" + content + " />";
}
function server(id) {
  document.getElementById(id).innerHTML = document.getElementsByName("n" + id)[0].value;
  document.getElementById(id).style.background = "#ff0000";
  document.getElementById(id).style.color = "#ffffff";
  document.getElementById(id).onclick = function(){
        Modify(this);
    }
}
</script>
<table width="255" height="28" border="0" cellpadding="0" cellspacing="1" bgcolor="#CCCCCC" style="font-size:12px; font-family:Arial;">
  <tr>
    <td width="213" height="26" bgcolor="#FFFFFF" id="td_1"  onclick="Modify(this)" >修改</td>
    <td width="39" bgcolor="#FFFFFF" ><a href="#" onclick="server('td_1')">保存</a></td>
  </tr>
</table>