It is not really you; obviously you are using a back office to create
these pages, using some type of form to post articles and content.
When you posted the Adsense code this backoffice or template area, the
programming changed the code from "code" to HTML formated text, which
is why you can see it like that on the page. For example the
backoffice functions replaced all of the <'s with <'s ...
template area without this conversion. The programming is doing what
it was designed to do, ... I don't want to give the impression that
this is an error... it is a feature actually. The programming helps
you post and create HTML pages without having to know anything about
HTML, while allowing you to bold words or make titles, etc.
What you want to find out (or look for) is the tags that tell the
nature. The one labeled CODE will probably just format the code as an
example area (change the color of the text to green or something, but
still alter it so that you would be seeing it as you do now). Its for
displaying example code on a webpage for instructional purposes.
If you can not find it, or your program doesn't have this
functionality (many don't), then you will need to contact your
tech-support people in order to have that functionality added to your