这段js老是没得到我要的效果。。郁闷

<table id="oTable" border="1">

            <thead>

                <tr>

                    <th>

                        第一列

                    </th>

                    <th>

                        第二列

                    </th>

                    <th>

                        第三列

                    </th>

                </tr>

            </thead>

            <tr>

                <td style="background-color: red; color: white">

                    Cell 1, Row 1

                </td>

                <td>

                    Cell 2, Row 1

                </td>

                <td style="background-color: blue; color: white">

                    Cell 3, Row 1

                </td>

            </tr>

            <tr>

                <td style="background-color: red; color: white">

                    Cell 1, Row 2

                </td>

                <td>

                    Cell 2, Row 2

                </td>

                <td style="background-color: blue; color: white">

                    Cell 3, Row 2

                </td>

            </tr>

            <tr>

                <td style="background-color: red; color: white">

                    Cell 1, Row 3

                </td>

                <td>

                    Cell 2, Row 3

                </td>

                <td style="background-color: blue; color: white">

                    Cell 3, Row 3

                </td>

            </tr>

        </table>

<input type="button" value="点击" onclick="swapTableCol()" />

        <script type="text/javascript">

            function sortedTable(tableid) {

                var sorted = '第三列,第一列,第二列';

                var sortedHeader = sorted.split(',');

                var tableHeader = [];

                var table = document.getElementById(tableid);

                if (table.rows.length > 0) {

                    var headers = table.rows[0].getElementsByTagName("th");

                    for (var i = 0; i < headers.length; i++) {

                        tableHeader[i] = headers[i].innerText;

                    }

                    var sortedTmpHeader;

                    var tableTmpHeader;

                    var arr = new Array();



                    var length = sortedHeader.length > tableHeader.length ? tableHeader.length : sortedHeader.length;

                    for (var i = 0; i < length; i++) {

                        sortedTmpHeader = sortedHeader[i];

                        for (var j = 0; j < tableHeader.length; j++) {

                            if (trim(sortedTmpHeader) == trim(tableHeader[j])) {

                                arr.push((j + '-' + i));

                                break;

                            }

                        }

                    }



                    if (arr.length > 0) {

                        var copyRows = new Object();

                        for (var i = 0; i < table.rows.length; i++) {

                            copyRows[i] = table.rows[i].cloneNode(true);

                       } 



                        var firstIndex;

                        var secondIndex;

                        var parentNode;

                        var newChild;

                        var oldChild;

                        

                        for (var i = 0; i < arr.length; i++) {

                            firstIndex = parseInt(arr[i].split('-')[0]);

                            secondIndex = parseInt(arr[i].split('-')[1]);

                            for (var j = 0; j < table.rows.length; j++) {

                                parentNode = table.rows[j];

                                newChild = copyRows[j].childNodes[secondIndex].cloneNode(true);

                                oldChild = table.rows[j].cells[firstIndex];

                               // if (parentNode && newChild && oldChild) {

                                    parentNode.insertBefore(newChild, oldChild);

                                    parentNode.removeChild(oldChild);

                               // }

                            }

                        }

                    }

                }

            }



            function swapTableCol(objTbl, col1, col2) {

//                objTbl = document.getElementById(objTbl);

//                for (var i = 0; i < objTbl.rows.length; i++) {

//                    swapNode(objTbl.rows[i].cells[col1], objTbl.rows[i].cells[col2]);

                //                }

                sortedTable('oTable');

            }



            function trim(str) {

                var str = str + "";

                return str.replace(/^\s+|\s+$/, "");

            }



            function swapNode(node1, node2) {

                var parent = node1.parentNode; //父节点

                var t1 = node1.nextSibling; //两节点的相对位置

                var t2 = node2.nextSibling;

                if (t1)

                    parent.insertBefore(node2, t1);

                else

                    parent.appendChild(node2);

                if (t2)

                    parent.insertBefore(node1, t2);

                else

                    parent.appendChild(node1);

            }           

        </script>

我想将 table 的列左右移动。。但是不行。
问题出在这一段。我估计是 子节点的问题
for (var j = 0; j < table.rows.length; j++) {
parentNode = table.rows[j];
newChild = copyRows[j].childNodes[secondIndex].cloneNode(true);
oldChild = table.rows[j].cells[firstIndex];
// if (parentNode && newChild && oldChild) {
parentNode.insertBefore(newChild, oldChild);
parentNode.removeChild(oldChild);
// }
}