just three things:
You have noticed your layout XML doesn't include a TabHost? Might be the problem.
Take a look at my XML code (first post in this thread). Basically, you can c+p everything until the first ScrollView, then, instead of the three ScrollViews, put your LinearLayout containing the button there, and naturally, close the tags. Then you have a TabHost, a FrameLayout and everything you need to reference stuff from your Activity (which by the way should be a TabActivity).
I'm not sure if you can actually use setContent(Intent), and I'm also not sure what you're trying to accomplish there. If, what I assume, you want your Button to have an Intent, the way to go probably would be something like:
Using java Syntax Highlighting
((Button) getViewById(R.id.button)).setIntent(new Intent(...))
Parsed in 0.030 seconds, using GeSHi
Please, for the next posts, put your code in syntax tags. Makes it more readable.
Also, this tutorial
might help you understanding TabLayouts/TabActivities.
A la fin, il y aura seulement de la beauté.