Adsense + CustomLayout problem


I’m trying to add adsense block inside a CustomLayout, but i can’t make it works. This is the layout template.

<div id="adsense" style="width:100%;text-align:center;">
	<script>alert("Hello test")</script>
	<script type="text/javascript"><!--
		google_ad_client = "xx-xxx-11111111111111";
		/* Test */
		google_ad_slot = "22222222";
		google_ad_width = 728; 
		google_ad_height = 90;
	<script type="text/javascript" src=""></script>

“Hello test” alert is showing properly but adsense script isn’t doing anything.

I’ve try the script overriding “writeAjaxPageHtmlHeader” using page.append and it works. Why doesn’t work inside a CustomLayout? I’m missing something? Is there any other way to do this?