fix the layout issue in larger screen

Author: Gary Hua

res/layout/main.xml

@@ -21,7 +21,7 @@
     android:orientation="vertical" >
 
     <LinearLayout
-        android:layout_width="wrap_content"
+        android:layout_width="fill_parent"
         android:layout_height="0dip"
         android:layout_weight="1"
         android:background="@drawable/background"
@@ -164,15 +164,14 @@
     </LinearLayout>
 
     <LinearLayout
-        android:layout_width="wrap_content"
+        android:layout_width="fill_parent"
         android:layout_height="wrap_content"
-        android:background="@drawable/background_key"
-        android:orientation="horizontal" >
+        android:gravity="center"
+        android:background="@drawable/background_key" >
 
         <LinearLayout
             android:layout_width="wrap_content"
             android:layout_height="wrap_content"
-            android:layout_gravity="center"
             android:orientation="horizontal" >
 
             <ImageButton