js表格添加删除行2

<script type="text/javascript" language="javascript">
       // 添加一行
       function AddTR(tabId) {
           var TB = document.getElementById(tabId);
           var mTr = TB.rows[TB.rows.length - 1];
           var TR = TB.insertRow(TB.rows.length);
           for (var i = 0; i <= mTr.cells.length - 1; i++) {
               TR.insertCell(i);
               TR.cells[i].innerHTML = mTr.cells[i].innerHTML;
               var inputs = TR.cells[i].getElementsByTagName("input");
               for (var j = 0; j < inputs.length; j++) {
                   if (inputs[j].getAttribute("type") == "text") {
                       inputs[j].value = "";
                       inputs[j].readOnly = "";
                   }
                   if (inputs[j].getAttribute("type") == "hidden") {
                       inputs[j].value = "0";
                   }
                   if (inputs[j].getAttribute("type") == "button") {
                       inputs[j].disabled = false;
                   }
               }
               var selects = TR.cells[i].getElementsByTagName("select");
               if (selects.length > 0) selects[0].selectedIndex = 0;
               var textarea = TR.cells[i].getElementsByTagName("textarea");
               if (textarea.length > 0) textarea[0].value = "";
           }
       }
       // 删除一行
       function DelTR(tabId, obj) {
           var TB = document.getElementById(tabId);
           if (TB.rows.length > 2) {
               obj.parentNode.parentNode.parentNode.removeChild(obj.parentNode.parentNode);
           } else {
               alert("至少保留一条！");
           }
       }
    </script>