用Jquery自己开发个代阴影的对话框吧！

<script type="text/javascript" src="http://img.zzl.com/script/jquery/jquery-1.4.2.min.js"></script>
<script type="text/javascript">
    $(function() {
        $("#open").click(function() {
            openDialog(a1); //调用,直接写上DIV的ID即可
        });
    });
    var openDialog = function(o) {
        var dialog = new zzlDialog(o);
        dialog.open();
    }
    var zzlDialog = function(o) {
        this.init = function() {
            /* 对话框初始化 */
            var XBox = '\
                 <div id="mask"/>\
                <div id="wai">\
                </div>\
                <div id="nie">\
                    <table>\
                        <thead>\
                            <tr>\
                                <td>\
                                    阴影弹出框\
                                </td>\
                                <td>\
                                </td>\
                            </tr>\
                        </thead>\
                        <tbody>\
                            <tr>\
                                <td colspan="2">' + $(o).html() + '\
                                </td>\
                            </tr>\
                        </tbody>\
                    </table>\
                </div>\
                    ';
            $(document.body).append(XBox);
        };

        this.cssInit = function() {
            /* css初始化 */
            $("#wai").css({ "padding": "10px", "background": "#000", "filter": "Alpha(Opacity='50')", "position": "absolute" });
            $("#nie").css({ "position": "absolute", "z-index": "1000" });
            $("#nie>table").css({ "border": "1px solid rgb(55,119,188)", "border-collapse": "collapse", "background": "#fff" });
            $("#nie>table>thead>tr").css({ "background": "rgb(0,94,172)", "color": "#fff", "height": "30px", "font-size": "14px", "font-weight": "bold" });
            $("#nie>table").find("td").css({ "padding": "5"});
            /* 内部主体定位 */
            $("#nie").css({ "top": "50px" });
            $("#nie").css({ "left": "50px" });
            /* 关闭按钮 */
            var $close = $("#nie>table>thead").find("td").next("td");
            $close.html("<span>关闭</span>");
            $close.css({ "text-align": "right", "padding-right": "5px" });
            $close.find("span").css({ "font-weight": "normal", "cursor": "hand" });
            $close.find("span").click(function() { new zzlDialog().closes(); });
            /* 外部阴影添加 ,及位置和大小由内部内容来控制 */
            $("#wai").css({ "width": ($("#nie>table").width() + 16) + "px", "height": ($("#nie>table").height() + 16) + "px" });
            $("#wai").css({ "top": $("#nie").position().top - 8 + "px", "left": $("#nie").position().left - 8 + "px", "z-index": $("#nie").css("z-index") });
         //   $("#wai").corner("5px"); //圆角
        };
        this.open = function() {
            this.init();
            this.cssInit();
            this.shadow();
        };
        this.shadow = function() {
            this.event_b_show();
            if (window.attachEvent) {
                window.attachEvent('onresize', this.event_b);
                window.attachEvent('onscroll', this.event_b);
            }
            else {
                window.addEventListener('resize', this.event_b, false);
                window.addEventListener('scroll', this.event_b, false);
            }
        };

        this.event_b = function() {
            var oShadow = $('#mask');
            if (oShadow.css("display") != "none") {
                if (this.event_b_show) {
                    this.event_b_show();
                }
            }
        };
        this.closes = function() {
            var oShadow = $('#mask');
            oShadow.css({ 'display': 'none' });
            $("#wai").remove();
            $("#nie").remove();
        };
        this.event_b_show = function() {
            var oShadow = $('#mask');
            oShadow.css({ 'position': 'absolute', 'display': '', 'opacity': '0.1', 'filter': 'alpha(opacity=10)', 'background': '#000' });
            var sClientWidth = parent ? parent.document.body.offsetWidth : document.body.offsetWidth;
            var sClientHeight = parent ? parent.document.body.offsetHeight : document.body.offsetHeight;
            var sScrollTop = parent ? (parent.document.body.scrollTop + parent.document.documentElement.scrollTop) : (document.body.scrollTop + document.documentElement.scrollTop);
            oShadow.css({ 'top': '0px', 'left': '0px', 'width': sClientWidth + "px", 'height': (sClientHeight + sScrollTop) + "px" });