<script language="JavaScript">
<!--
var reference_row = current_form.textName.length;
// Get the table body
var tbody_node = document.getElementById("tablebody");//tbody的id为tablebody
// Get the reference row element
var reference_node = tbody_node.childNodes[reference_row];
// Create the new <tr> element
var new_tr_node = document.createElement("tr");
var inserted_node = tbody_node.insertBefore(new_tr_node, reference_node);
// Get the number of columns
//var table_columns = reference_node.childNodes.length;
var td1_node = document.createElement("td"); // 1
inserted_node.appendChild(td1_node);
var textName_node = document.createElement("<input type='text' name='textName'>");
td1_node.appendChild(textName_node);