也面弹出一个登陆窗口，怎么做到？

参考
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"><html xmlns="http://www.w3.org/1999/xhtml">
<head>
    <title></title>
    <style type="text/css">
        .login
        {
         border-width:2px;
         border-color:Blue;
         background:Yellow;
         z-index:1001;
         height:30px;
         height:200px;
         width:200px;
         /*display:none 不能写在这里*/
        }
        .btm /*半透明层*/
        {
         position:absolute;
         left:0;
         top:0;
         height:100%;
         width:100%;
            background:#000;
            filter: alpha(opacity=50);
            -moz-opacity:0.5;
            opacity: 0.5;
            z-index:1000;
            /*display:none 不能写在这里*/
        }
    </style>
    <script type="text/javascript">
        function opendiv() {
            var getLoginDiv = document.getElementById("login");
            var getbtm = document.getElementById("btm");
            getLoginDiv.style.display = "";
            getbtm.style.display = "";
        }
        function cancel() {
            var getLoginDiv = document.getElementById("login");
            var getbtm = document.getElementById("btm");
            getLoginDiv.style.display = "none";
            getbtm.style.display = "none";
        }
//        function _mousemove() {
//            var xx = window.event.clientX;
//            var yy = window.event.clientY;
//            var getLoginDiv = document.getElementById("login");
//            getLoginDiv.style.top = xx;
//            getLoginDiv.style.left = yy;
//        }
    </script>
</head>
<body>
<a href="javascript:opendiv()">登陆</a>
<div id="login" class="login" style="display:none;position:absolute;top:30%;left:30%;">
<a  style="float:right;" href="javascript:cancel()">取消</a>
<br />
    <input style="float:left;" id="userName" />
     <br /><br />

    <input id="Password" type="password" /> <br /><br />
    <input id="btn" type="button" value="改变" onclick="" />
</div>
<div id="btm" style="display:none;" class="btm"></div>
</body>
</html>

+1 用个背景层遮盖。
需要弹出的div居中显示 ~

div 绝对定位，显示在最上面就可以了

<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title></title>
<style>
    #shadowDiv {
        display: none;
        width: 100%;
        height: 100%;
        position: absolute;
        top:0;
        left:0;
        background-color:#000000;
        filter: alpha(opacity = 60);
        opacity: 0.6;
        z-index: 999;
    }
    #login {
     position: absolute;
     background-color:#fff;
     top:50%;
     left:50%;
     margin-top:-50px;
     margin-left:-150px;
         z-index:1000;
         height:100px;
         width:300px;
         display:none;
    }</style>
<script>
    var register =function(){

        showShadowDiv();document.getElementById("login").style.display="block";
    }
    var showShadowDiv = function(){
        var d = document.createElement("DIV");
        d.id = "shadowDiv";
        document.body.insertBefore(d, document.body.firstChild);
        d.style.display='block';
        d.style.height=document.documentElement.clientHeight;
    }
</script>
</head>
    <body>
    <input  type="button" onclick="register();"/>
    <div id="login">
      账号：  <input  type="text" /><br />
      密码：  <input  type="text" /><br />
      <input type="button" value="确定" />
    </div>
    </body>
</html>参考下。

div 块就可以啊
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
  <head>
    <title>dragDiv.html</title>

    <meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
    <meta http-equiv="description" content="this is my page">
    <meta http-equiv="content-type" content="text/html; charset=UTF-8">
<style type="text/css">
body {
font-family:Verfana;
font-size:11px;
color:#333333;
}
#win {
position:absolute;
left:250px;
top:250px;
width:200px;
height:150px;
border:1px solid #000000;
background: #0af934;
}
</style>
<script type="text/javascript">
var win;
var left = 50;
var top = 50;
var move = false;
function init() {
    win = document.getElementById("win");
    win.onmousedown = startDrag;
    win.onmousemove = drag;
    win.onmouseup = stopDrag;
}

window.onload = init;

function startDrag(event) {
event = event || window.event;
var x = event.pageX || event.x;
        var y = event.pageY || event.y;
        left = x - left;
        top = y - top;
        win.style.background = "red";
        move = true;
}

function drag(event) {
    if(move) {
event = event || window.event;
        win.style.background = "blue";
        var x = event.pageX || event.x;
         var y = event.pageY || event.y;
        win.style.left = x - left + "px";
        win.style.top = y - top + "px";
        //captureEvents();
        //win.setCapture();
        if (!window.captureEvents) {
    win.setCapture();
} else {
captureEvents();
    //window.captureEvents(Event.MOUSEMOVE|Event.MOUSEUP);
}
    }
}

function stopDrag(event) {
event = event || window.event;
    win.style.background="yellow";
    var x = event.pageX || event.x;
        var y = event.pageY || event.y;
    left = x - left;
    top = y - top;
    move = false;
    //routeEvent();
    //win.releaseCapture();
    if (!window.releaseEvents) {
        win.releaseCapture();
} else {
releaseEvents();
        //window.releaseEvents(Event.MOUSEMOVE|Event.MOUSEUP);
}
} function toggleWin() {
var w = document.getElementById("win");
if (w.style.display == "none")
w.style.display = "block";
else
w.style.display = "none";
}
</script>
  </head>

<body>
<input type="button" value="login/cancel" onclick="toggleWin()"/>
<div id="win">

</div>
</body>
</html>
在div中放置登陆内容，还可以加一个按钮取消登陆也行

调试易

也面弹出一个登陆窗口，怎么做到？

解决方案 »