<div id='banner'>Banner</div>

<script type='text/javascript'>
var now = new Date();
var sec = now.getSeconds();
var sec = sec % 2;
if (sec == 0) {
var url = "http://www.gorod.hmsite.net/ru/uslugi.html";
var alt = "Размещение рекламы на GORODCOM";
var banner = "http://www.gorod.hmsite.net/ru/banners/portal.gif";
var width = "300";
var height = "250";
} else {
var url = "http://www.gorod.hmsite.net/ru/clients/gri_ukraina/index.html";
var alt = "ГРИ ВМУРОЛ УКРАИНА";
var banner = "http://www.gorod.hmsite.net/ru/banners/ukraina.gif";
var width = "300";
var height = "250";
}

document.getElementById("banner").innerHTML = ("<center><a href='" + url + "' target='_top'><img src='" + banner + "' width='" + width + "' height='" + height + "' alt='" + alt + "' border='0'></a></center>");

</script>