why i can't add adsense in my theme or in my signature

This is code

Code:

<script type="text/javascript"><!--
google_ad_client = "pub-8475907847995691";
/* 468x60, ñúçäàäåí 09-1-20 */
google_ad_slot = "6431580997";
google_ad_width = 468;
google_ad_height = 60;
//-->
</script>
<script type="text/javascript"
src="http://pagead2.googlesyndication.com/pagead/show_ads.js">
</script>

hey, do you have html code enabled?

Drag~

Yes

Does the code itself appear in the signature?
Also do you attach the signature?

Why not write the code in google and Signatures in my profile

I would like to correct myself, its not possible to add codes to your signature since html is not turned on for signatures.