var loadTip = "<div>���װ���У����Ժ�...</div>";
function Zid(idstr) {
	try {
		return window.document.getElementById(idstr);
	} catch (e) {
		alert("function Zid:" + e.description);
	}
}
function send_request(url, postData, aObjectID) { // ��ʼ����ָ�����?��������ĺ���
	// ��ʼ��ʼ��XMLHttpRequest����

	var http_request;
	if (window.XMLHttpRequest) { // Mozilla �����
		http_request = new XMLHttpRequest();
		if (http_request.overrideMimeType) {// ����MiME���
			http_request.overrideMimeType("text/xml");
		}
	} else if (window.ActiveXObject) { // IE�����
		try {
			http_request = new ActiveXObject("Msxml2.XMLHTTP");
		} catch (e) {
			try {
				http_request = new ActiveXObject("Microsoft.XMLHTTP");
			} catch (e) {
			}
		}
	}
	if (!http_request) { // �쳣����������ʵ��ʧ��
		window.alert("���ܴ���XMLHttpRequest����ʵ��.");
		return false;
	}
	http_request.onreadystatechange = getReadyStateHandler(http_request,
			aObjectID);
	// ȷ����������ķ�ʽ��URL�Լ��Ƿ�ͬ��ִ���¶δ���
	http_request.open("POST", url, true);
	http_request.setRequestHeader("Content-Type",
			"application/x-www-form-urlencoded");
	http_request.send(postData);
}
function getReadyStateHandler(req, aObjectID) {
	// ����һ������XMLHttpRequestʵ���������
	return function() {
		// ��������״̬�ǡ���ɡ�
		if (req.readyState == 4) {
			// �ɹ������˷�������Ӧ
			if (req.status == 200) {
				var temp = Zid(aObjectID);
				if (temp == null) {
					alert('can not find object');
				} else {
					temp.style.display = "";
					temp.innerHTML = req.responseText;
				}
			} else {
				// ��HTTP���ⷢ��
				alert("HTTP error: " + req.status);
			}
		}
	}
}
function expand(aObjectID) {

	var spanChild = Zid(aObjectID + "child");
	if (spanChild.innerHTML != "") {
		// ͼƬ����
		if (spanChild.style.display == "") {
			Zid(aObjectID + "img").src = treeImagePath + treeCloseImg;
			spanChild.style.display = "none";
		} else if (spanChild.style.display == "none") {
			Zid(aObjectID + "img").src = treeImagePath + treeOpenImg;
			spanChild.style.display = "";
		}
	} else {
		Zid(aObjectID + "img").src = treeImagePath + treeOpenImg;
		spanChild.innerHTML = loadTip;
		var postData = "nodeID=" + aObjectID + "&buildSelf=false";
		send_request(url, postData, aObjectID + "child");
	}
}

// ˢ�¸�nodeID�ڵ�
function refreshNode(nodeID) {
	var postData;
	var aDivObject;
	if (nodeID == "") {
		nodeID = "rootID";
		postData = "nodeID=&buildSelf=true";
	} else {
		postData = "nodeID=" + nodeID + "&buildSelf=true";
	}
	aDivObject = Zid(nodeID);
	aDivObject.innerHTML = loadTip;
	send_request(url, postData, nodeID);
}
function openNewPage() {
	window.open(url, null,
			"height=600,width=800,status=0,toolbar=0,scrollbars=1");
}