var how_many_ads = 3;
var now = new Date()
var sec = now.getSeconds()
var ad = sec % how_many_ads;
ad +=1;
if (ad==1) {
url="<script language='javascript' src='http://www2.smart-quotes.com/Creatives/DisplayImage.aspx?id=546&ctc=589&src=1125&cmpg=&web=&brn=175&type=js'></script>";
}
if (ad==2) {
url="<script language='javascript' src='http://www2.smart-quotes.com/Creatives/DisplayImage.aspx?id=2855&ctc=589&src=1125&cmpg=&web=&brn=175&type=js'></script>";
}
if (ad==3) {
url="<script language='javascript' src='http://www2.smart-quotes.com/Creatives/DisplayImage.aspx?id=4454&ctc=589&src=1125&cmpg=&web=&brn=175&type=js'></script>";
}

document.write('' + url + '');