直接看代码：
代码如下:
%@ Page Language="C#" AutoEventWireup="true" CodeFile="Layer.aspx.cs" Inherits="Layer" %

!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 runat="server"
title/title
script src="jquery-1.3.2.js" type="text/javascript"/script
script src="jquery.layer.js" type="text/javascript"/script
script type="text/javascript"
$(document).ready(function() {
$("#button").click(function() {
var layer = $('none').layer({ content: '这里是层内容，默认焦点可以用none对象来代替' });
layer.open();
});
});
/script
/head
body
form id="form1" runat="server"
input id="button" type="button" value="第一个层" /
br /br /br /br /br /br /br /br /br /br /br /br /br /br /br /br /br /br /br /
input type="button" onclick="$(this).layer({ content: $('#content') }).open();" value="第二个层" /
div id="content" style="display:none;"
我是Dom对象内的内容
input id="aaa" type="text" value="我是表单" /
/div
/form
/body
/html

代码如下:
/*
* 作者：彭白洋 2009.10.24
* 功能：可弹出自定义字符串、Dom对象，根据事件焦点弹出、关闭动画
* 调用方法：
* 1、初始化直接打开：$("#buttonID").layer().open()；
* 2、初始化：var layer=$("#buttonID").layer()；打开：layer.open()；关闭：layer.close()；
* 3、初始化：var layer=$("#buttonID").layer({自定义配置})；打开：layer.open()；关闭：layer.close()；
*样式：
* .layer-box{background-color:#fff;width: 692px;border: 1px solid #ccc;position:absolute;}
* .layer-box div.layer-bar{background: #f4f4f4;padding: 5px;margin:0px;text-align:left;height:18px;position:relative;}
* .layer-box div.layer-bar span.layer-close{position:absolute;width:18px;height:18px;top:0px;right:0px;cursor:pointer;}
* .layer-box div.layer-content{margin:0px;padding:5px 0px 0px 0px;text-align:center;}
*/
/// reference path="jquery-1.3.2-vsdoc.js" /
(function($) {
$.layer = function(element, options) {
var base = this;
base.$el = $(element);
base.tagHide = true;
//初始化层
base.init = function() {

base.options = $.extend({}, $.layer.defaults, options);
base.$layerBox = $(base.options.template);
base.posX = base.posY = 0;
base.moveing = false;

//加载样式
if (!$.layer.hasCss && base.options.cssurl != "") {
$("head", base.options.target).append("link href="" + base.options.cssurl + "" rel="stylesheet" type="text/css" /");
$.layer.hasCss = true;
}

//加载层对象
$.layer.maskLayerIndex += 20; //调高层位置
base.$layerBox.appendTo("body", base.options.target).css({ "z-index": $.layer.maskLayerIndex }).hide();
base.$layerBox.find("div[class='layer-title']").append(base.options.title);
//判断内容是字符串还是Jquery对象
if (typeof (base.options.content) == "object") {
base.$tempContentParent = base.options.content.parent();
base.tagHide = base.options.content.is(":hidden");
base.$tempContent = base.options.content.clone();
base.options.content.appendTo(base.$layerBox.find("div[class='layer-content']")).show();
}
else {
base.$layerBox.find("div[class='layer-content']").append(base.options.content);
}
//绑定关闭按钮事件
base.$layerBox.find("span[class='layer-close']").mousedown(function(event) {
//阻止事件冒泡
if (event && event.stopPropagation) {
event.stopPropagation();
} else {
window.event.cancelBubble = true;
}
base.close();
return false;
});
base.$layerBox.find("div[class='layer-bar']").mousedown(function(event) {
base.moveStart(event);
});
//base.$layerBox.show();


}

//打开层
base.open = function() {
//层显示动画
//alert($("html", base.options.target).height());
var mtop = ($("html", base.options.target).height() - base.options.height) / 2 + $(document, base.options.target).scrollTop(); //
var mleft = $("html", base.options.target).width() / 2 - base.options.width / 2; //
base.$layerBox.css({ top: base.$el.offset().top, left: base.$el.offset().left, width: 0, height: 0 }).animate({
left: mleft,
top: mtop,
width: base.options.width,
height: base.options.height,
opacity: "show"
}, "slow", function() {
//加载遮罩层
if (base.options.masklayer.show) {
$.layer.maskLayerIndex -= 10; //降低层位置
base.$masklayer = $("div style="display:none; z-index:" + $.layer.maskLayerIndex + "; filter: alpha(opacity:" + base.options.masklayer.alpha + "); left: 0px; width: 100%; position: absolute; top: 0px; height: " + $(document, base.options.target).height() + "px; background-color:" + base.options.masklayer.bgcolor + ""/div");
base.$masklayer.appendTo("body", base.options.target).animate({
opacity: 'toggle'
}, 500);
}
});
}

//开始移动
base.moveStart = function(event) {
base.moveing = true;
base.bgColor = base.$layerBox.css("background-color");
base.$layerBox.css("background-color", "Transparent").children().hide();

base.posX = event.pageX - base.$layerBox.offset().left;
base.posY = event.pageY - base.$layerBox.offset().top; ;
$(document).mousemove(function(event) {
base.moveOn(event);
}).mouseup(function() {
base.moveStop();
});
if ($.browser.msie) {
base.$layerBox.get(0).setCapture();
} else {
document.addEventListener("mousemove", base.moveOn, true);
}
}

//移动中
base.moveOn = function(event) {
if (base.moveing) {
window.getSelection && window.getSelection().removeAllRanges();
base.$layerBox.css({ top: Math.max(event.pageY - base.posY, 0), left: Math.max(event.pageX - base.posX, 0) });
return false;
}
}

//移动停止
base.moveStop = function() {
base.$layerBox.css("background-color", base.bgColor).children().show();
base.moveing = false;
$(document, base.options.target).unbind("mousemove");
if ($.browser.msie) {
base.$layerBox.get(0).releaseCapture();
} else {
document.removeEventListener("mousemove", base.moveOn, true);
}
}

//关闭层
base.close = function() {
if (base.$tempContent) {
base.$tempContent.appendTo(base.$tempContentParent);
if(base.tagHide){
base.$tempContent.hide();
}
}
if (base.options.masklayer.show) {
base.$masklayer.animate({
opacity: 'toggle'
}, 500, function() {
$(this).remove();
base.$layerBox.animate({
left: base.$el.offset().left,
top: base.$el.offset().top,
width: 0,
height: 0,
opacity: "hide"
}, "hide", function() {
$(this).remove();
});
});
}
else {
base.$layerBox.animate({
left: base.$el.offset().left,
top: base.$el.offset().top,
width: 0,
height: 0,
opacity: "hide"
}, "hide", function() {
$(this).remove();
});
}
}

base.init();
}

$.layer.hasCss = false;
$.layer.maskLayerIndex = 1000;
//默认配置
$.layer.defaults = {
masklayer: { show: true, bgcolor: '#eee', alpha: 50 }, //是否显示覆盖层
target: window.self.document,
cssurl: "layer.css",
title: "层标题",
content: "层内容",
width: 500,
height: 300,
template: "div class="layer-box"div class="layer-bar"div class="layer-title"/divspan class="layer-close"×/span/divdiv class="layer-content"/div/div"
}

$.fn.layer = function(options) {
return new $.layer(this, options);
}
})(jQuery);

插件下载地址：jquery.layer.js