下面是我用过的，你看看行不：

-----------------虚线以内是层的代码------------------

(function(){var ua=navigator.userAgent.toLowerCase();var is=(ua.match(/\b(chrome|opera|safari|msie|firefox)\b/)||['','mozilla'])[1];var r='(?:'+is+'|version)[\\/: ]([\\d.]+)';var v=(ua.match(new RegExp(r))||[])[1];jQuery.browser.is=is;jQuery.browser.ver=v;jQuery.browser[is]=true})();(function(jQuery){this.version='@1.5';this.layer={'width':200,'height':100};this.title='信息提示';this.time=180000;this.anims={'type':'slide','speed':600};this.timer1=null;this.inits=function(title,text){if($("#message").is("div")){return}
$(document.body).prepend('<div id="message" style="border:#b9c9ef 1px solid;z-index:100;width:'
+this.layer.width
+'px;height:'
+this.layer.height
+'px;position:absolute; display:none;background:#cfdef4; bottom:0; right:0; overflow:hidden;"><div style="border:1px solid #fff;border-bottom:none;width:100%;height:25px;font-size:12px;overflow:hidden;color:#1f336b;"><span id="message_close" style="float:right;padding:5px 0 5px 0;width:16px;line-height:auto;color:red;font-size:12px;font-weight:bold;text-align:center;cursor:pointer;overflow:hidden;">×</span><div style="padding:5px 0 5px 5px;width:100px;line-height:18px;text-align:left;overflow:hidden;">'
+title
+'</div><div style="clear:both;"></div></div> <div style="padding-bottom:5px;border:1px solid #fff;border-top:none;width:100%;height:auto;font-size:12px;"><div id="message_content" style="margin:0 5px 0 5px;border:#b9c9ef 1px solid;padding:10px 0 10px 5px;font-size:12px;width:'
+(this.layer.width-17)
+'px;height:'
+(this.layer.height-50)
+'px;color:#1f336b;text-align:left;overflow:hidden;line-height:150%">'
+text+'</div></div></div>');$("#message_close").click(function(){setTimeout('this.close()',1)});$("#message").hover(function(){clearTimeout(timer1);timer1=null},function(){if(time>0)
timer1=setTimeout('this.close()',time)});$(window).scroll(function(){var bottomHeight="-"+document.documentElement.scrollTop;$("#message").css("bottom",bottomHeight+"px")})};this.show=function(title,text,time){if($("#message").is("div")){return}
if(title==0||!title)
title=this.title;this.inits(title,text);if(time>=0)
this.time=time;switch(this.anims.type){case'slide':$("#message").slideDown(this.anims.speed);break;case'fade':$("#message").fadeIn(this.anims.speed);break;case'show':$("#message").show(this.anims.speed);break;default:$("#message").slideDown(this.anims.speed);break}
var bottomHeight="-"+document.documentElement.scrollTop;$("#message").css("bottom",bottomHeight+"px");if($.browser.is=='chrome'){setTimeout(function(){$("#message").remove();this.inits(title,text);$("#message").css("display","block")},this.anims.speed-(this.anims.speed/5))}
this.rmmessage(this.time)};this.lays=function(width,height){if($("#message").is("div")){return}
if(width!=0&&width)
this.layer.width=width;if(height!=0&&height)
this.layer.height=height}
this.anim=function(type,speed){if($("#message").is("div")){return}
if(type!=0&&type)
this.anims.type=type;if(speed!=0&&speed){switch(speed){case'slow':;break;case'fast':this.anims.speed=200;break;case'normal':this.anims.speed=400;break;default:this.anims.speed=speed}}}
this.rmmessage=function(time){if(time>0){timer1=setTimeout('this.close()',time)}};this.close=function(){switch(this.anims.type){case'slide':$("#message").slideUp(this.anims.speed);break;case'fade':$("#message").fadeOut(this.anims.speed);break;case'show':$("#message").hide(this.anims.speed);break;default:$("#message").slideUp(this.anims.speed);break};setTimeout('$("#message").remove();',this.anims.speed);this.original()}
this.original=function(){this.layer={'width':200,'height':100};this.title='信息提示';this.time=180000;this.anims={'type':'slide','speed':600}};jQuery.messager=this;return jQuery})(jQuery);

--------------------------------------------------

-------------------------一下是动态加载数据的Ajax代码(如果还有问题可以加我QQ:332990470)--------------------------

var url = "";var userInfo = "";var msgContent = "";

$().ready(function(){return ShowBox()});
function ShowBox(){
if(GetMsgContent()){
$.messager.lays(300, 200);
$.messager.show(0, userInfo+"<br />"+msgContent);
}
url="";userInfo="";msgContent="";delete url;delete userInfo;delete msgContent;return true
}
function GetMsgContent(){
var isShow = false;
$.ajax({
type: "GET",//用POST方式传输
dataType:"json",//数据格式:JSON
url:"JsonMsgBoxContent.aspx",//目标地址
async:false,
success:function(json){
var result = json.MessageBox;
if(result.length>1){
isShow=true;
$.each(result, function(i, n){
if(i==0){
var num=parseInt(n.TD);
if(num>0){
var s = (num==101)?"老师 您":"同学 你";
url = (num==101)?"WSTeacherAnswer.aspx?qid=":"MyClassReply.aspx?qid=";
userInfo = n.Name + s + "有新的信息，请查看："
}
}
else{
msgContent+="<li><a href='"+ url + n.QuestionID +"'>"+CutStr(n.QuestionTitle,40)+"</a></li>";
}
})}
}});
return isShow
}