function checkLogin()
{
	/*
	if (typeof MSG_NEED_USERNAME == "undefined")
		var MSG_NEED_USERNAME = "Please fill username";

	if (typeof MSG_NEED_PASSWORD == "undefined")
		var MSG_NEED_PASSWORD = "Please fill password";
	*/

	var node = document.getElementById("loginForm");
	if (node == null) return false;

	if (node.username.value == "")
	{
		alert(MSG_NEED_USERNAME);
		node.username.focus();
		return false;
	}

	if (node.password.value == "")
	{
		alert(MSG_NEED_PASSWORD);
		node.password.focus();
		return false;
	}
	else
	{
		var pwdmask = "********************************";
		//var md5key  = MD5(node.password.value);
		//var cypkey  = md5key.substr(0,4) + node.login_key.value.substr(0,4);
		var cypkey = node.login_key.value.substr(0,8);
                node.encrypt_pwd.value = stringToBase64(des(cypkey, node.password.value, 1));
		node.password.value    = pwdmask.substr(0,node.password.value.length);
	}
	return true;
}

/*****
// 重新產生 Login Key
// 20 分鐘後失效， 19 分鐘時重新產生
******/
setTimeout(function () {
	var timeout = 1140000;
	var xmlHttp = null;
	var regenUrl = "/sys/door/regen_loginkey.php";

	var setLoginKey = function (val) {
		var node = document.getElementById("loginForm");
		if (node == null) return false;
		node.login_key.value = val;
	};

	var jQueryStep = function () {
		jQuery.ajax({
			type: "POST",
			url: regenUrl,
			success: function(msg){
				setLoginKey(msg);
			}
		});

		setTimeout(jQueryStep, timeout);
	};
	var XmlHttpStep = function () {
		xmlHttp.open("POST", regenUrl, false);
		xmlHttp.send(null);
		setLoginKey(xmlHttp.responseText);

		setTimeout(XmlHttpStep, timeout);
	};

	if (typeof jQuery != "undefined") {
		jQueryStep();
	} else if (typeof XmlHttp != "undefined") {
		xmlHttp = XmlHttp.create();
		XmlHttpStep();
	}
}, 1140000);