title: Eclypse:the method add(int fragment) in the type fragmenttransaction is not applicable
body: <p>Im starting Android developing and learning java. My problem is the "the method add(int fragment) in the type fragmenttransaction is not applicable" error in</p>
  
  <pre><code>     package com.example.myfirstapp;
      import android.annotation.SuppressLint;
      import android.annotation.TargetApi;
      import android.app.Fragment;
      import android.os.Build;
      import android.os.Bundle;
      import android.support.v7.app.ActionBarActivity;
      import android.view.LayoutInflater;
      import android.view.MenuItem;
      import android.view.View;
      import android.view.ViewGroup;
      @TargetApi(Build.VERSION_CODES.HONEYCOMB)
      @SuppressLint("NewApi")
      public class DisplayMessageActivity extends ActionBarActivity {
          @Override
          protected void onCreate(Bundle savedInstanceState) {
              super.onCreate(savedInstanceState);
              setContentView(R.layout.activity_display_message);
  
              if (savedInstanceState == null) {
                  getSupportFragmentManager().beginTransaction()
     &lt;==here==&gt;             .add(R.id.container, new PlaceholderFragment()).commit();
              }
          }
          @Override
          public boolean onOptionsItemSelected(MenuItem item) {
              // Handle action bar item clicks here. The action bar will
              // automatically handle clicks on the Home/Up button, so long
              // as you specify a parent activity in AndroidManifest.xml.
              int id = item.getItemId();
              if (id == R.id.action_settings) {
                  return true;
              }
              return super.onOptionsItemSelected(item);
          }
  
          public static class PlaceholderFragment extends Fragment {
              public PlaceholderFragment() { }
              @Override
              public View onCreateView(LayoutInflater inflater, ViewGroup container,
                        Bundle savedInstanceState) {
                    View rootView = inflater.inflate(R.layout.activity_display_message,
                            container, false);
                    return rootView;
              }
          }
      }
  </code></pre>
  
  <p>when i used import android.support.v4.app.Fragment; elypse show no error but on my phone app crash
  Thanks For Help!</p>