Android java.lang.NoClassDefFoundError: org.jsoup.Jsoup

I work with eclipse Version: Indigo Service Release 2 Build id: 20120216-1857. The Android version ist 2.2. I make an app to test a connect and parse a web site like this:

public class TestActivity extends Activity {
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);

    try {
        Document doc = Jsoup.connect("http://example.com/").get();
        Elements divs = doc.select("div#test");

    for (Element div : divs) {
            System.out.println(div.text());
    }
    } catch (Exception e) {
    }
    }
}

Manifest file:

android:installLocation="preferExternal"
android:versionCode="1"
android:versionName="1.0" >

<uses-sdk android:minSdkVersion="8" />
<uses-permission android:name="android.permission.INTERNET" />

<application
    android:icon="@drawable/ic_launcher"
    android:label="@string/app_name" >
    <activity
        android:name=".TestActivity"
        android:label="@string/app_name"
    android:configChanges="orientation"
    >
        <intent-filter>
            <action android:name="android.intent.action.MAIN" />

            <category android:name="android.intent.category.LAUNCHER" />
        </intent-filter>            
        <uses-library android :name="org.jsoup.Jsoup" />
    </activity>
</application>

I add the library jsoup-1.6.1.jar to JAVA Buildpath, but I become the runtime error: E/AndroidRuntime(736): java.lang.NoClassDefFoundError: org.jsoup.Jsoup

How can I resolve this error?