var how_many_ads = 2;
var now = new Date()
var sec = now.getSeconds()
var ad = sec % how_many_ads;
ad +=1;
if (ad==1) {
url="join.htm";
alt="Sunita";
banner="thumb_sunita.jpg";
width="220";
height="220";
}
if (ad==2) {
url="join.htm";
alt="Valery Summer";
banner="thumb_valery.jpg";
width="220";
height="220";
}

document.write('<center>');
document.write('<a href=\"' + url + '\" target=\"_blank\">');
document.write('<img src=\"' + banner + '\" width=')
document.write(width + ' height=' + height + ' ');
document.write('alt=\"' + alt + '\"><br>');
document.write('</center>');