title: element <com.google.android.gms.ads.AdView> is unknown
body: <p>I'm trying to add ad-mobs ads into my android application I've installed Google play services 17 package and copied the package from the sdk>extras>google>google play service to my work space>myproject>lib>__ and imported the google-play-service_lib file to my workspace.
  after that I added google-play-service.jar to my project>java build path >libraries and I also checked order and export.</p>
  
  <p>But in vain I'm getting an error in main.xml for Element  com.google.andriod.gsm.ads.AdView is unknown but it compiles and launches the activity in emluator but has an runtime error. </p>
  
  <p>I've gone through so many posts but none did make me clear enough. </p>
  
  <p>Here below is the mainfest of my project:</p>
  
  <pre><code>&lt;?xml version="1.0" encoding="utf-8"?&gt;
  &lt;manifest xmlns:android="http://schemas.android.com/apk/res/android"
  package="com.SAI.banner"
  android:versionCode="1"
  android:versionName="1.0" &gt;
  
  &lt;uses-sdk
      android:minSdkVersion="11"
      android:targetSdkVersion="19" /&gt;
  
   &lt;uses-permission android:name="android.permission.INTERNET"/&gt;
  &lt;uses-permission android:name="android.permission.ACCESS_NETWORK_STATE"/&gt;
  
  
  &lt;application
      android:allowBackup="true"
      android:icon="@drawable/ic_launcher"
      android:label="@string/app_name"
      android:theme="@style/AppTheme" &gt;
      &lt;meta-data android:name="com.google.android.gms.version"
             android:value="@integer/google_play_services_version"/&gt;
  
      &lt;activity
          android:name="com.SAI.banner.MainActivity"
          android:label="@string/app_name" &gt;
          &lt;intent-filter&gt;
              &lt;action android:name="android.intent.action.MAIN" /&gt;
  
              &lt;category android:name="android.intent.category.LAUNCHER" /&gt;
          &lt;/intent-filter&gt;
      &lt;/activity&gt;
      &lt;activity android:name="com.google.android.gms.ads.AdActivity"
           android:configChanges="keyboard|keyboardHidden|orientation|screenLayout|uiMode|screenSize|smallestScreenSize"/&gt;
  
  &lt;/application&gt;
  
  &lt;/manifest&gt;
  </code></pre>
  
  <p>Main.xml :</p>
  
  <pre><code>&lt;RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
  xmlns:tools="http://schemas.android.com/tools"
  xmlns:ads="http://schemas.android.com/apk/res-auto"
  android:layout_width="match_parent"
  android:layout_height="match_parent"
  android:paddingBottom="@dimen/activity_vertical_margin"
  android:paddingLeft="@dimen/activity_horizontal_margin"
  android:paddingRight="@dimen/activity_horizontal_margin"
  android:paddingTop="@dimen/activity_vertical_margin"
  android:background="@drawable/bg"
  tools:context="com.SAI.banner.MainActivity$PlaceholderFragment" &gt;
  
  &lt;TextView
      android:id="@+id/textView1"
      android:layout_width="wrap_content"
      android:layout_height="wrap_content"
      android:layout_alignParentTop="true"
      android:layout_centerHorizontal="true"
      android:layout_marginTop="20dp"
      android:text="@string/hello_world" /&gt;
  
  &lt;com.google.android.gms.ads.AdView
      android:id="@+id/adView"
      android:layout_width="wrap_content"
      android:layout_height="wrap_content"
      android:layout_below="@+id/textView1"
      android:layout_centerHorizontal="true"
      android:layout_marginTop="60dp"
      ads:adSize="BANNER"
      ads:adUnitId="ca-app-pub-3131326757457805/934xxxxxxx" &gt;
  &lt;/com.google.android.gms.ads.AdView&gt;
  
  &lt;/RelativeLayout&gt;
  </code></pre>
  
  <p>The MainActivity.java </p>
  
  <pre><code>package com.SAI.banner;
  
  import android.support.v7.app.ActionBarActivity;
  import com.google.android.gms.ads.*;
  import android.os.Bundle;
  
  public class MainActivity extends ActionBarActivity {
  
  @Override
  protected void onCreate(Bundle savedInstanceState) {
      super.onCreate(savedInstanceState);
      setContentView(R.layout.activity_main);
  
      // Look up the AdView as a resource and load a request.
      AdView adView = (AdView)this.findViewById(R.id.adView);
      AdRequest adRequest = new AdRequest.Builder().build();
      adView.loadAd(adRequest);
  }
  }
  </code></pre>
  
  <p>Thanks in advance Saikiran. 
  Please help me to solve this.</p>