var nAds = 4;
var now = new Date()
var sec = now.getSeconds()
var ad = sec % nAds;
ad +=1;

if (ad==1) {
banner='<a href="http://ad.zanox.com/ppc/?14244239C181877475T"><img src="http://ad.zanox.com/ppv/?14244239C181877475" align="bottom" width="250" height="250" border="0" hspace="1" alt="hivers_2010_250x250"></a>';
}

if (ad==2) {
banner='<a href="http://ad.zanox.com/ppc/?13958321C1462632186T"><img src="http://ad.zanox.com/ppv/?13958321C1462632186" align="bottom" width="250" height="250" border="0" hspace="1" alt="sejour_250x250_20ko.gif"></a>';
}

if (ad==3) {
banner='<a href="http://ad.zanox.com/ppc/?8035976C271618878T"><img src="http://ad.zanox.com/ppv/?8035976C271618878" align="bottom" width="250" height="250" border="0" hspace="1" alt="Multi_250x250_20ko.gif"></a>';
}
if (ad==4) {
banner='<a href="http://ad.zanox.com/ppc/?8562310C1877869189T"><img src="http://ad.zanox.com/ppv/?8562310C1877869189" align="bottom" width="250" height="250" border="0" hspace="1" alt="ski_250x250_20ko"></a>';
}
document.write(banner);