var how_many_ads = 10;
var now = new Date()
var sec = now.getSeconds()
var ad = sec % how_many_ads;
ad +=1;

if (ad==1) {
url="c_previsao2.shtml";
alt="";
banner="ran/v07.gif";
width="138";
height="140";
}

if (ad==2) {
url="c_previsao2.shtml";
alt="";
banner="ran/v07.gif";
width="138";
height="140";
}
if (ad==3) {
url="c_sinastria.shtml";
alt="";
banner="ran/v11.gif";
width="138";
height="140";
}
if (ad==4) {
url="c_previsao3.shtml";
alt="";
banner="ran/v15.gif";
width="138";
height="140";
}
if (ad==5) {
url="c_astronomia.shtml";
alt="";
banner="ran/v19.gif";
width="138";
height="140";
}
if (ad==6) {
url="c_empresarial.shtml";
alt="";
banner="ran/v23.gif";
width="138";
height="140";
}
if (ad==7) {
url="c_mito.shtml";
alt="";
banner="ran/v27.gif";
width="138";
height="140";
}
if (ad==8) {
url="c_saude.shtml";
alt="";
banner="ran/v31.gif";
width="138";
height="140";
}
if (ad==9) {
url="c_astrovivencia.shtml";
alt="";
banner="ran/vastrovi.gif";
width="138";
height="140";
}
if (ad==10) {
url="c_pint.shtml";
alt="";
banner="ran/vpint.gif";
width="138";
height="140";
}