点击登录，动态显示登录层
<!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>
<script type="text/javascript">
function loginShow() {
var LoginDiv = document.getElementById("LoginDiv");
LoginDiv.style.display = '';
}
function Loginhide() {
var LoginDiv = document.getElementById("LoginDiv");
LoginDiv.style.display ="none";
}
</script>
</head>
<body>
<a href="javascript:loginShow()">登录</a>
<div id="LoginDiv" style=" border-color:Red; border-width:thin; border-style:solid; position:absolute; top:200px; left:200px; display:none">
<img src="Images/close.jpg" style=" float:right;" onmouseover="Loginhide()" />
<table>
<tr><td><label for="userName">用户名：</label></td><td><input type="text" id="userName" /></td></tr>
<tr><td><label for="passWord">密码：</label></td><td><input type="text" id="passWord" /></td></tr>
</table>
</div>
</body>
</html>
<html xmlns="http://www.w3.org/1999/xhtml" >
<head>
<title></title>
<script type="text/javascript">
function loginShow() {
var LoginDiv = document.getElementById("LoginDiv");
LoginDiv.style.display = '';
}
function Loginhide() {
var LoginDiv = document.getElementById("LoginDiv");
LoginDiv.style.display ="none";
}
</script>
</head>
<body>
<a href="javascript:loginShow()">登录</a>
<div id="LoginDiv" style=" border-color:Red; border-width:thin; border-style:solid; position:absolute; top:200px; left:200px; display:none">
<img src="Images/close.jpg" style=" float:right;" onmouseover="Loginhide()" />
<table>
<tr><td><label for="userName">用户名：</label></td><td><input type="text" id="userName" /></td></tr>
<tr><td><label for="passWord">密码：</label></td><td><input type="text" id="passWord" /></td></tr>
</table>
</div>
</body>
</html>
