var how_many_ads = 15;
var now = new Date()
var sec = now.getSeconds()
var ad = sec % how_many_ads;
ad +=1;
if (ad==1) {
txt="";
url="";
alt="";
banner="foto_u_pilani/01.jpg";
width="120";
height="111";
}
if (ad==2) {
txt="";
url="";
alt="";
banner="foto_u_pilani/02.jpg";
width="120";
height="175";
}
if (ad==3) {
txt=""; 
url="";
alt="";
banner="foto_u_pilani/03.jpg";
width="120";
height="107";
}
if (ad==4) {
txt="";
url="";
alt="";
banner="foto_u_pilani/04.jpg";
width="120";
height="120";
}
if (ad==5) {
txt="";
url="";
alt="";
banner="foto_u_pilani/05.jpg";
width="120";
height="105";
}
if (ad==6) {
txt="";
url="";
alt="";
banner="foto_u_pilani/06.jpg";
width="120";
height="96";
}
if (ad==7) {
txt="";
url="";
alt="";
banner="foto_u_pilani/07.jpg";
width="120";
height="112";
}
if (ad==8) {
txt="";
url="";
alt="";
banner="foto_u_pilani/08.jpg";
width="120";
height="101";
}
if (ad==9) {
txt="";
url="";
alt="";
banner="foto_u_pilani/09.jpg";
width="120";
height="104";
}
if (ad==10) {
txt="";
url="";
alt="";
banner="foto_u_pilani/10.jpg";
width="120";
height="107";
}
if (ad==11) {
txt="";
url="";
alt="";
banner="foto_u_pilani/11.jpg";
width="120";
height="173";
}
if (ad==12) {
txt="";
url="";
alt="";
banner="foto_u_pilani/12.jpg";
width="120";
height="176";
}
if (ad==13) {
txt="";
url="";
alt="";
banner="foto_u_pilani/13.jpg";
width="120";
height="102";
}
if (ad==14) {
txt="";
url="";
alt="";
banner="foto_u_pilani/14.jpg";
width="120";
height="103";
}
if (ad==15) {
txt="";
url="";
alt="";
banner="foto_u_pilani/15.jpg";
width="120";
height="112";
}
document.write('<center>');
document.write('<a href=\"' + url + '\" target=\"_top\">');
document.write('<img class="img" src=\"' + banner + '\" width=')
document.write(width + ' height=' + height + ' ');
document.write('alt=\"' + alt + '\" border=0><br>');
document.write('<small>' + txt + '</small></a>');
document.write('</center>');