Código PHP:
<?
//Code adsense
$content = '
<script type="text/javascript"><!--
google_ad_client = "xxxxx";
google_ad_width = 120;
google_ad_height = 240;
google_ad_format = "120x240_as";
google_ad_type = "text";
google_ad_channel ="";
google_page_url = document.location;
google_color_border = "DFE6EF";
google_color_bg = "DFE6EF";
google_color_link = "2A63C1";
google_color_url = "C00000";
google_color_text = "000000";
//--></script>
<script type="text/javascript"
src="">
</script>';
// Centrado
echo"<div align='center'>
<center>
<table border='0' cellspacing='1' width='5%'>
<tr>
<td width='100%'>
<p align='center'>$content</td>
</tr>
</table></center>
</div>";
?>
Saludos.-