var how_many_ads = 5;
var now = new Date()
var sec = now.getSeconds()
var ad = sec % how_many_ads;
ad +=1;

if (ad==1) {
url="http://www.ynfox.com/ra";
alt="RA2 DIY";
banner="css/banner/banner01.gif";
}

if (ad==2) {
url="http://www.ynfox.com";
alt="云狐网";
banner="css/banner/banner02.gif";
}

if (ad==3) {
url="http://www.ynfox.com/ra";
alt="红警扩展程序之『兵临城下』";
banner="css/banner/banner03.gif";
}

if (ad==4) {
url="http://www.ynfox.com/music";
alt="天籁音乐网";
banner="css/banner/banner04.gif";
}

if (ad==5) {
url="http://www.site.net.cn";
alt="昆明锦绣网景科技有限公司";
banner="css/banner/banner05.gif";
}

document.write('<a href=\"' + url + '\">');
document.write('<img src=\"' + banner + '\" width=468 height=60 ')
document.write('alt=\"' + alt + '\" border=0></a>');