i am developing a simple app in Android. Whenever i change orientation to landscape one of my buttons get lost when i run APP on MOBILE device but my landscape view works fine with Andriod Simulator on PC. Other then this , APP works fine on Mobile Device.I am using TABLE LAYOUT for the landscape orientation. Below is my code please check where is the problem. Also ECLIPSE shows that "This LinearLayout layout or its LinearLayout parent is useless" why is that.
res/layout/activity_sudoku.xml
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:padding="30dip"
android:orientation="horizontal" >
<LinearLayout
android:orientation="vertical"
android:layout_height="wrap_content"
android:layout_width="fill_parent"
android:layout_gravity="center">
<TextView
android:id="@+id/textView1"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_gravity="center"
android:layout_marginBottom="25dip"
android:text="@string/main_title" />
<Button
android:id="@+id/button1"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="@string/continue_label" />
<Button
android:id="@+id/button2"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_marginTop="21dp"
android:text="@string/new_game_label" />
<Button
android:id="@+id/button3"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_marginTop="20dp"
android:text="@string/about_label" />
<Button
android:id="@+id/button4"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_marginTop="29dp"
android:text="@string/exit_label" />
</LinearLayout>
</LinearLayout>
(FOR LANDSCAPE VIEW)res/layout-land/activity_sudoku.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:padding="15dip"
android:orientation="horizontal" >
<LinearLayout
android:orientation="vertical"
android:layout_height="wrap_content"
android:layout_width="fill_parent"
android:layout_gravity="center"
android:paddingLeft="20dip"
android:paddingRight="20dip">
<TextView
android:text="@string/main_title"
android:layout_height="wrap_content"
android:layout_width="wrap_content"
android:layout_gravity="center"
android:layout_marginBottom="20dip"
android:textSize="24.5sp" />
<TableLayout
android:layout_height="wrap_content"
android:layout_width="wrap_content"
android:layout_gravity="center"
android:stretchColumns="*">
<TableRow>
<Button
android:id="@+id/button1"
android:text="@string/continue_label" />
<Button
android:id="@+id/button2"
android:text="@string/new_game_label" />
</TableRow>
<TableRow>
<Button
android:id="@+id/button3"
android:text="@string/about_label" />
<Button
android:id="@+id/button4"
android:text="@string/exit_label" />
</TableRow>
</TableLayout>
</LinearLayout>
</LinearLayout>