function Loigndemand() {
    var bool = $("#jizhu").attr("checked");
    xmlHttp = null;
    xmlHttp = GetXmlHttpObject();
    if (xmlHttp == null) {
        alert("您的浏览器不支持AJAX！");
        return;
    }
    var url = "Logindemand.aspx?username=" + escape(document.getElementById("username").value) + "&userpass=" + escape(document.getElementById("password").value)+"&bool="+bool;

    xmlHttp.open("GET", url, true);
    xmlHttp.onreadystatechange = LoigndemandBack;
    xmlHttp.send(null);
}
function LoigndemandBack() {
    if (xmlHttp.readyState == 4) {
        if (xmlHttp.status == 200) {
            var strs = xmlHttp.responseText;
            var string = strs.split(",");
            if (string[0] == "1") {
                document.getElementById("username_lefttop").innerHTML = string[1];
            }
            else {
                alert("登录失败");
                return false;
            }
        }
    }
}