Apps Admob implementation issue help needed

[frond]

Please I need your help. I'm truggling to implement google Admob Banner in my app but it's male functioning. When I put the admob code in the activity_main.xml, in the relative layout block, my content doesn't appear but ad is displayed and when I remove the banner code from the layout, the app works fine.

Here is the code:

activity_main:

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
   xmlns:app="http://schemas.android.com/apk/res-auto"
   xmlns:tools="http://schemas.android.com/tools"
   android:id="@+id/activity_main"
   android:layout_width="match_parent"
   android:layout_height="match_parent"
   android:eek:rientation="vertical"
   tools:context="com.myapp.hello.MainActivity">

   <RelativeLayout
       android:layout_width="match_parent"
       android:layout_height="wrap_content"
       android:background="@color/topColor">

       <ImageView
           android:id="@+id/app_icon"
           android:layout_width="40dp"
           android:layout_height="40dp"
           android:layout_alignParentLeft="true"
           android:layout_marginLeft="10dp"
           android:layout_marginTop="3dp"
           android:background="@drawable/back_img"
           android:src="@drawable/in_app_icon" />

       <TextView
           android:id="@+id/app_name"
           android:layout_width="wrap_content"
           android:layout_height="wrap_content"
           android:layout_marginLeft="5dp"
           android:layout_marginTop="10dp"
           android:layout_toRightOf="@+id/app_icon"
           android:text="@string/app_name"
           android:textColor="#000"
           android:textSize="24dp" />

       <com.astuetz.PagerSlidingTabStrip
           android:id="@+id/tabs"
           android:layout_width="match_parent"
           android:layout_height="wrap_content"
           android:layout_below="@id/app_icon"
           android:layout_gravity="center_vertical"
           android:layout_marginTop="20dp"
           android:paddingBottom="8dp"
           app:pstsDividerColor="@color/topColor"
           app:pstsIndicatorHeight="4dp"
           app:pstsTabPaddingLeftRight="10dp"
            />

       <com.google.android.gms.ads.AdView
           xmlns:ads="http://schemas.android.com/apk/res-auto"
           android:id="@+id/adView"
           android:layout_width="wrap_content"
           android:layout_height="wrap_content"
           android:layout_centerHorizontal="true"
           android:layout_alignParentBottom="true"
           ads:adSize="BANNER"
           ads:adUnitId="ca-app-pub-3940256099942544/6300978111">
       </com.google.android.gms.ads.AdView>

   </RelativeLayout>


   <android.support.v4.view.ViewPager
       android:id="@+id/pager"
       android:layout_width="match_parent"
       android:layout_height="wrap_content"
       android:layout_above="@+id/bottom"
       android:layout_below="@+id/tabs"

       android:cacheColorHint="#00000000"
       android:scrollbars="none"

       />
</LinearLayout>

and the MainActivity.java:

public class MainActivity extends FragmentActivity implements ViewPager.OnPageChangeListener { private AdView mAdView;
ViewPager pager;
PagerSlidingTabStrip tabs;
private int previousPage = 0;
List<Fragment> fragment;
TextView app_name;
private int[] imageResId = { R.drawable.selectore_tab1, R.drawable.01, R.drawable.02  };
@Override
protected void onCreate(Bundle savedInstanceState) {
   super.onCreate(savedInstanceState);
   setContentView(R.layout.activity_main);


   if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
       getWindow().addFlags(WindowManager.LayoutParams.FLAG_DRAWS_SYSTEM_BAR_BACKGROUNDS);
       getWindow().setStatusBarColor(getResources().getColor(R.color.topbar));
   }


   pager=(ViewPager)findViewById(R.id.pager);
   tabs = (PagerSlidingTabStrip)findViewById(R.id.tabs);
   tabs.setShouldExpand(true);
   LinearLayout view = (LinearLayout) tabs.getChildAt(0);
   app_name=(TextView)findViewById(R.id.app_name) ;
   Typeface face = Typeface.createFromAsset(getAssets(),
           "fonts/Android Insomnia Regular.ttf");
   app_name.setTypeface(face);
   tabs.setOnPageChangeListener(this);

   pager = (ViewPager) findViewById(R.id.pager);
   //adapter = new MyPagerAdapter(getSupportFragmentManager());
   fragment = new ArrayList<Fragment>();
   fragment.add(new Fragment1());
   fragment.add(new Fragment2());
   fragment.add(new Fragment3());

   // pager.setAdapter(new CustomPagerAdapter(getSupportFragmentManager(),fragment));
   pager.setAdapter(new MainAdapter(getSupportFragmentManager(),imageResId));

   tabs.setViewPager(pager);
   tabs.setIndicatorColor(Color.parseColor("#000000"));


   MobileAds.initialize(this, "ca-app-pub-3940256099942544~3347511713");

//
   mAdView = (AdView)findViewById(R.id.adView);
   AdRequest adRequest = new AdRequest.Builder().build();
   mAdView.loadAd(adRequest);
//

}

Thanks in advance!!!