<td width="10%" title="双击修改" ondblclick="ShowElement(this,<%#Eval("id") %>
</td>

function ShowElement(element, productid, flag, ishotorcommend) {
  if (flag == 0 && ishotorcommend == 0) {
    alert("请先设置该产品为推荐");
    return;
  }
  if (flag == 1 && ishotorcommend == 0) {
    alert("请先设置该产品为热销");
    return;
  }
  var oldhtml = element.innerHTML;//原单元格里的值
  var str = "<input type='text' name='test' style='width:50%;'";
  str += "onkeypress='return event.keyCode>=48&&event.keyCode<=57||event.keyCode==46'";
  str += "onpaste='return !clipboardData.getData('text').match(/\D/)'";
  str += "ondragenter='return false' />";
  var newobj = document.createElement(str);  //创建新的input元素
  newobj.setAttribute("value", oldhtml);//把原来单元格中的值赋给文本框
  newobj.onblur = function() {
    element.innerHTML = this.value "UpdateFlag.ashx" + sort + "&&productid=" + productid + "&&flag=" + flag, function(data) { });
  }
  element.innerHTML = '';
  element.appendChild(newobj);//把新的值赋到单元格
  newobj.focus();
}