var xmlHttp;
    //创建xmlHttp  
    function createXMLHttpRequest() {
        if (window.XMLHttpRequest) {// code for IE7+, Firefox, Chrome, Opera, Safari
            xmlHttp = new XMLHttpRequest();
        } else {// code for IE6, IE5
            xmlHttp = new ActiveXObject("Microsoft.XMLHTTP");
        }
    }

    function doRequestUsingGet(obj) {
        if (obj.value == "") {
            var dis = document.getElementById("DivSelect");
            dis.innerHTML = "";
            return null;
        }
        createXMLHttpRequest();
        var url = "./auditajax.htm?branName=" + obj.value;
        xmlHttp.open("GET", url, true);
        xmlHttp.setRequestHeader("Content-Type",
                "application/x-www-form-urlencoded; charset=GBK");
        xmlHttp.onreadystatechange = function() {
            if (xmlHttp.readyState == 4) {
                if (xmlHttp.status == 200) {
                    updateBran();
                }
            }
        };
        xmlHttp.send(null);
    }

    function updateBran() {
        var doc = new ActiveXObject("MSxml2.DOMDocument");
        doc.loadXML(xmlHttp.responseText);
        var confs = doc.getElementsByTagName("conf");
        var dis = document.getElementById("DivSelect");
        dis.innerHTML = "";
        for ( var i = 0; i < confs.length; i++) {
            var bran_name = confs[i].selectSingleNode("bran_name").text;//取结点里的数据
            var bank_name = confs[i].selectSingleNode("bank_name").text;
            var bran_no = confs[i].selectSingleNode("bran_no").text;
            dis.innerHTML += "<div class='autoItem'  id='autoItem' style='height:20px;background-color: white;border-color: red;border: 2px;'>"
                    + bank_name + "</div>";
        }

        e = window.event;
        document.onkeydown = function(e) {
            if (document.getElementById("DivSelect")) {
                e = window.event || e;
                switch (e.keyCode) {
                case 38:
                    // 上方向键
                    currentLine--;
                    changeItem();
                    break;
                case 40:
                    // 下方向键
                    currentLine++;
                    changeItem();
                    break;
                case 32:
                    document.body.appendChild(divtable);
                    break;
                default:
                    break;
                }
            }
        };


求changeItem()的方法构思～～～ 怎么获取DIV下的所有节点