仿MSN右下角弹出广告代码并自动消失

<SCRIPT Language=javascript>
<!--
var oPopup = window.createPopup();
var popTop=50;
function popmsg(msgstr){
var winstr="<table width=\"241\" height=\"180\" border=\"0\" cellpadding=\"0\" cellspacing=\"0\">";
winstr+="<tr><td align=\"center\"><table width=\"90%\" height=\"180\" border=\"0\" cellpadding=\"0\" cellspacing=\"0\">";
winstr+="<tr><td align=\"center\"><table width=\"90%\" height=\"180\" border=\"0\" cellpadding=\"0\" cellspacing=\"0\">";
winstr+="<tr><td valign=\"top\" style=\"font-size:12px;\">"+msgstr+"</td></tr></table></td></tr></table>";
oPopup.document.body.innerHTML = winstr;
popshow();
}
function popshow(){
window.status=popTop;
if(popTop>1720){
clearTimeout(mytime);
oPopup.hide();
return;
}else if(popTop>1520&&popTop<1720){
oPopup.show(screen.width-250,screen.height,241,1720-popTop);
}else if(popTop>1500&&popTop<1520){
oPopup.show(screen.width-250,screen.height+(popTop-1720),241,172);
}else if(popTop<180){
oPopup.show(screen.width-250,screen.height,241,popTop);
}else if(popTop<220){
oPopup.show(screen.width-250,screen.height-popTop,241,180);
}
popTop+=10;
var mytime=setTimeout("popshow();",60);
}
popmsg("<DIV align=center><br>欢迎您的光临:<a href=http://hi.baidu.com/6878>我的BLOG</a><br><br>MAIL：qiaozhigao@163.com<br> OICQ：77567759<br><br><font color=red>合作者:SOHU,3721,21CN...<br>站长资源</font></DIV>");
-->
</SCRIPT>