Adsense block not displaying anything

Question

I have copied and pasted the following code into my page, but it seems to be having no effect. It should have a fall back block colour, but nothing is showing.

Code copied/pasted straight from google

    <script type="text/javascript"><!--
google_ad_client = "ca-pub-7972043490779920";
/* SALF */
google_ad_slot = "4085311300";
google_ad_width = 300;
google_ad_height = 250;
//-->
</script>
<script type="text/javascript"
src="http://pagead2.googlesyndication.com/pagead/show_ads.js">
</script>

Answer 1

In my experience, sometimes it just take about 10 minutes for adsense to display ads, IF you are running ads for the first time on that website .

also in some cases you must have some keywords for adsense to display relevant ads .

and in some other cases, for exemple if your domain is an adult domain with some adult keywords in the domain name it will not show ads at all .