Ecco i codici che uso...
Codice HTML:
<script type="text/javascript">
//<![CDATA[
google_color_border = "003399";
google_color_bg = "33BBFF";
google_color_link = "0033CC";
google_color_url = "008000";
google_color_text = "000000";
document.write('<s'+'cript type="text/javascript" src="http://ad.altervista.org/js.ad/size=728X90/r='+new Date().getTime()+'"><\/s'+'cript>');
//]]>
</script>
[...]
<script type="text/javascript">
//<![CDATA[
document.write('<s'+'cript type="text/javascript" src="http://ad.altervista.org/js.ad/size=125X125/r='+new Date().getTime()+'"><\/s'+'cript>');
//]]>
</script>