title: cannot convert from android.app.FragmentManager to android.support.v4.app.FragmentManager
body: <p>I am creating an app using Fragments for tablet.I have so far created some buttons on the left side and the fragments appear on clicking the buttons.</p>
  
  <p>But i am experiencing error in my MainActivity.java file "Type mismatch error:cannot convert from <code>android.app.FragmentManager</code> to <code>android.support.v4.app.FragmentManager</code>" And that is the main reason that i cannot implement it.I have already imported <code>android.support.v4.app.FragmentManager</code>.</p>
  
  <p>How can i resolve my problem?</p>
  
  <p>My code for MainActivity.java</p>
  
  <pre><code>      import android.app.Activity;
  import android.os.Bundle;
  import android.support.v4.app.Fragment;
  import android.support.v4.app.FragmentManager;
  import android.support.v4.app.FragmentTransaction;
  import android.view.View;
  import android.widget.Button;
  
  public class MainActivity extends Activity {
      Fragment fragment;
      Button btn1,btn2,btn3,btn4,btn5,btn6;
      @Override
      protected void onCreate(Bundle savedInstanceState) {
          super.onCreate(savedInstanceState);
          setContentView(R.layout.activity_main);
          btn1=(Button)findViewById(R.id.btn1);
          btn2=(Button)findViewById(R.id.btn2);
          btn3=(Button)findViewById(R.id.btn3);
          btn4=(Button)findViewById(R.id.btn4);
          btn5=(Button)findViewById(R.id.btn5);
          btn6=(Button)findViewById(R.id.btn6);
  
          FragmentManager fm=getFragmentManager();
          FragmentTransaction ft=fm.beginTransaction();
  
          StartFragment myfragment=new StartFragment();
          ft.add(R.id.myfragment,myfragment);
          ft.commit();
          btn4.setOnClickListener(btnOnClickListener);
          btn5.setOnClickListener(btnOnClickListener);
          btn6.setOnClickListener(btnOnClickListener);
      }
  
  
  
          Button.OnClickListener btnOnClickListener=new Button.OnClickListener(){
              @Override
  
              public void onClick(View v)
              {
                  Fragment newfragment;
                  if(v==btn1)
                  {
                      newfragment=new Fragment1();
                  }
                  else if(v==btn2)
                  {
                      newfragment=new Fragment2();
                  }
                  else if(v==btn3)
                  {
                      newfragment=new Fragment3();
                  }
                  else if(v==btn4)
                  {
                      newfragment=new Fragment4();
                  }
                  else if(v==btn5)
                  {
                      newfragment=new Fragment5();
                  }
                  else if(v==btn6)
                  {
                      newfragment=new Fragment6();
                  }
                  else 
                  {
                      newfragment=new StartFragment();
                  }
                  FragmentTransaction transaction=getFragmentManager.beginTransaction();
                  transaction.replace(R.id.myfragment,newfragment);
                  transaction.addToBackStack(null);
                  transaction.setTransition(FragmentTransaction.TRANSIT_FRAGMENT_FADE);
                  transaction.commit();
              }
          };
          }
  </code></pre>