Put Layout at bottom and add scrollbar
<p>I have three Relative layouts in may app, on above another.</p>

<pre><code>&lt;RelativeLayout_1&gt;&lt;CheckBox&gt;&lt;/CheckBox&gt;&lt;/RelativeLayout&gt;
&lt;RelativeLayout_2&gt;&lt;/RelativeLayout&gt;
&lt;RelativeLayout_3&gt;&lt;/RelativeLayout&gt;
</code></pre>

<p>First is at top, and third is at bottom. When I click on check box in my first layout, second layout is visible/unvisible. How to achive that I always see third layout at bottom and put scrollbar at second when is visible ? ( Second have lot off content so when is visible, third layout is vanished ).</p>
