Android UI: Align button at bottom of scrollview inside tabs

Referring to this tutorial below: http://www.droidnova.com/layout-technique-static-elements-below-scrollview,123.html The example above works but it is displaying button not inside a tab where as my code needs to display all elements within a Tab

I've tried modifying the code to include my design into a Tab but the button at the bottom is not displaying. I've attach my code to illustrate my problem

since new user can't post images, i've posted it at: http://i.stack.imgur.com/M3RH5.png

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"  android:orientation="vertical"  android:layout_height="wrap_content" android:layout_width="fill_parent">
<TabHost android:id="@android:id/tabhost" android:layout_width="fill_parent" android:layout_height="fill_parent">
    <LinearLayout android:layout_width="fill_parent" android:id="@+id/linearLayout1" android:layout_height="fill_parent" android:orientation="vertical">
        <TabWidget android:layout_width="fill_parent" android:layout_height="wrap_content" android:id="@android:id/tabs"></TabWidget>
            <FrameLayout android:layout_width="fill_parent" android:layout_height="fill_parent" android:id="@android:id/tabcontent">
           <LinearLayout android:layout_width="fill_parent" android:layout_height="fill_parent" android:id="@+id/tab1">

           <ScrollView android:layout_marginBottom="50dip" android:id="@+id/ScrollView01" android:layout_height="wrap_content" android:layout_width="fill_parent">
           <RadioGroup android:id="@+id/RadioGroup01" android:layout_width="wrap_content" android:layout_height="wrap_content">
           <RadioButton android:id="@+id/RadioButton01" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="Radio Button....." />
           <RadioButton android:id="@+id/RadioButton02" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="Radio Button....." />
           <RadioButton android:id="@+id/RadioButton02" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="Radio Button....." />
           <RadioButton android:id="@+id/RadioButton02" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="Radio Button....." />
           <RadioButton android:id="@+id/RadioBut开发者_如何学Pythonton02" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="Radio Button....." />
           <RadioButton android:id="@+id/RadioButton02" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="Radio Button....." />
           <RadioButton android:id="@+id/RadioButton02" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="Radio Button....." />
           <RadioButton android:id="@+id/RadioButton02" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="Radio Button....." />
           <RadioButton android:id="@+id/RadioButton02" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="Radio Button....." />
           <RadioButton android:id="@+id/RadioButton02" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="Radio Button....." />
           <RadioButton android:id="@+id/RadioButton02" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="Radio Button....." />
           <RadioButton android:id="@+id/RadioButton02" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="Radio Button....." />
           <RadioButton android:id="@+id/RadioButton02" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="Radio Button....." />
           <RadioButton android:id="@+id/RadioButton11" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="Radio Button....." />           
           </RadioGroup>
            </ScrollView>

        <RelativeLayout android:layout_marginTop="-50dip" android:gravity="bottom" android:layout_height="wrap_content" android:layout_width="fill_parent">
            <Button android:id="@+id/Button01" android:layout_height="wrap_content" android:layout_width="fill_parent" android:text="A button that should always be at the bottom"/>
        </RelativeLayout>

        </LinearLayout>
        <LinearLayout android:layout_width="fill_parent" android:layout_height="fill_parent" android:id="@+id/tab2"></LinearLayout>
        <LinearLayout android:layout_width="fill_parent" android:layout_height="fill_parent" android:id="@+id/tab3"></LinearLayout>
  </FrameLayout>
  </LinearLayout>
</TabHost>
</LinearLayout>

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enter both the buttons and scrollview inside the relative layout like

<Relativelayout>
<scrollview ......... />
<button ........../>
</relativelayout>

and make the button android:layout_alignParentBottom="true"