function getByClass(clsName, parent) {

    var oParent = parent ? document.getElementById(parent) : document,

        eles = [],

        elements = oParent.getElementsByTagName('*');

    for (var i = 0, l = elements.length; i < l; i++) {

        if (elements[i].className == clsName) {

            eles.push(elements[i]);

        }

    }

    return eles;

}

window.onload = drag;

function drag() {

    var oTitle = getByClass("login_logo_webqq", "loginPanel")[0];

    //拖页

    oTitle.onmousedown = fnDown;

    //关闭页面

    var close = document.getElementById("ui_boxyClose");

    close.onclick = winClose;

    //切换状态

    var loginState = document.getElementById("loginState");

    var stateList = document.getElementById("loginStatePanel");

    var lis = stateList.getElementsByTagName("li");

    var stateTxt = document.getElementById("login2qq_state_txt");

    var loginStateShow = document.getElementById("loginStateShow");

    //点击显示下拉单

    loginState.onclick = function (e) {

        stateList.style.display = "block";

        //阻止事件冒泡；

        e = event || window.event;

        if(e.stopPropagation){

            e.stopPropagation();

        }else{

            e.cancelBubble = true;

        }

    };

    //鼠标滑过,背景变色

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

        lis[i].onmouseover = function () {

            this.style.backgroundColor = "#888";

        };

        lis[i].onmouseout = function () {

            this.style.backgroundColor = "#fff";

        };

        //鼠标点击，txt改变，图标改变

        lis[i].onclick = function (e) {

            stateList.style.display = "none";

            //阻止事件冒泡

            e = event || window.event;

            if(typeof e.stopPropagation){

                e.stopPropagation();

            }else {

                e.cancelBubble = true;

            }

            var id = this.id;

            loginStateShow.className = "login-state-show "+id;

            var text = getByClass("stateSelect_text",id)[0].innerHTML;

            stateTxt.innerHTML = text;

        }

    }

    document.onclick = function () {

        stateList.style.display = "none";

    }

}

function winClose() {

    var box = document.getElementById("loginPanel");

    box.style.display = "none";

}

function fnDown(event) {

    var event = event || window.event;

    var oDrag = document.getElementById("loginPanel");

    //光标按下时光标和面板之间的距离；

    var disX = event.clientX - oDrag.offsetLeft;

    var disY = event.clientY - oDrag.offsetTop;

    //移动

    document.onmousemove = function (event) {

        event = event || window.event;

        fnMove(event, disX, disY);

    };

    document.onmouseup = function () {

        document.onmousemove = null;

        document.onmouseup = null;

    }

}

function fnMove(event, posX, posY) {

    var oDrag = document.getElementById("loginPanel");

    var l = event.clientX - posX;

    var t = event.clientY - posY;

    var winW = document.documentElement.clientWidth;

    var winH = document.documentElement.clientHeight;

    var maxW = winW - oDrag.offsetWidth - 10;

    var maxH = winH - oDrag.offsetHeight;

    //当l=0时，窗口不能继续外移

    if (l < 0) {

        l = 0;

    } else if (l > maxW) {

        l = maxW;

    }

    if (t < 10) {

        t = 10;

    } else if (t > maxH) {

        t = maxH;

    }

    oDrag.style.left = l + "px";

    oDrag.style.top = t + "px";

}