Android : plugin.xml is missing in Android

I want to create phone gap app in android.I have add cordova-2.0.0.jar file added in libs folder and build the path also and give the permission in Menifest file also.When i run the app the log cat says plugin.xml is missing.can someone give me idea here how to implement phone gap .Thanks to appreciate.

Here is my Button code

public class Start_Screen extends DroidGap
{
    Button btnLearn;
    Button btnExam;

    public void onCreate(Bundle SavedInstanceState)
    {
        super.onCreate(SavedInstanceState);

        setContentView(R.layout.starting_screen);
        overridePendingTransition(R.anim.abc_fade_in, R.anim.abc_fade_out);

        btnExam = (Button)findViewById(R.id.btnExam);
        btnExam.setOnClickListener(new OnClickListener() {

            @Override
            public void onClick(View v) {
                // TODO Auto-generated method stub
                loadUrl("file:///android_asset/www/message.html");
            }
        });
        }
} 

Here is log cat info 09-22 15:47:47.602: E/PluginManager(1339): ERROR: plugin.xml is missing. Add res/xml/plugins.xml to your project. 09-22 15:47:47.602: E/PluginManager(1339): https://git-wip-us.apache.org/repos/asf?p=incubator-cordova-android.git;a=blob;f=framework/res/xml/plugins.xml