how and where must add button in fragment class which is used for sliding menu?

I'm reading and working with a tutorial which is about how create sliding menu in android app ... the address of tutorial is this .. the activity-main.xml is this :

//activity-main.xml
<android.support.v4.widget.DrawerLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/drawer_layout"
android:layout_width="match_parent"
android:layout_height="match_parent">

<!-- Framelayout to display Fragments -->
<FrameLayout
    android:id="@+id/frame_container"
    android:layout_width="match_parent"
    android:layout_height="match_parent" />

<!-- Listview to display slider menu -->
<ListView
    android:id="@+id/list_slidermenu"
    android:layout_width="240dp"
    android:layout_height="match_parent"
    android:layout_gravity="start"
    android:choiceMode="singleChoice"
    android:divider="@color/list_divider"
    android:dividerHeight="1dp"        
    android:listSelector="@drawable/list_selector"
    android:background="@color/list_background"/>
  </android.support.v4.widget.DrawerLayout>

actually, I want to add a button to fragment_find_people.xml layout to show a simple toast ...

//fragment_find_people.xml
<?xml version="1.0" encoding="utf-8"?>
 <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent" >
<Button
    android:id="@+id/btnDelete"
    style="?android:attr/buttonStyleSmall"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
      android:text="enter" />
  </RelativeLayout>

i have not work with fragment class and view so i am confused ... i found out i could not create Button object in "FindPeopleFragment" class which extend Fragment .... there is class which is :

public class FindPeopleFragment extends Fragment {
Button btnAdd;
public FindPeopleFragment(){
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,Bundle savedInstanceState) {

    View rootView = inflater.inflate(R.layout.fragment_find_people, container, false);
    return rootView;

}

}

when I wrote :

    btnAdd=(Button)this.....

it shows no suggestion to find element by id ... no thing showed ... :( when I create a button in onCreate of MainActivity the program crashed !!!:(

public class MainActivity extends Activity {
protected void onCreate(Bundle savedInstanceState) {
..
...
..  
btnADD=(Button)this.findViewById(R.id.btnAdd);
btnADD.setOnClickListener(new clickListener());
}
.
class clickListener implements View.OnClickListener
{

    @Override
    public void onClick(View v) {
        // TODO Auto-generated method stub

    }

}
.
 }

where i must create my Button and call its OnClickListener ???

thanks for helping

You could add a layout which holds the listview inside of the sliding menu,and by this you could add views before / after the sliding menu. for example.

    <LinearLayout
        android:id="@+id/left_drawer"
        android:layout_width="320dp"
        android:layout_height="match_parent"
        android:layout_gravity="start"
        android:background="#fff"
        android:orientation="vertical" >
    <TextView
         android:id="@+id/user_fc"
         android:layout_width="match_parent"
         android:layout_height="wrap_content"
         android:layout_weight="0.04"
         android:gravity="left|center_vertical"
         android:layout_marginLeft="3dp"
         android:textStyle="italic" />
 <ListView
         android:id="@+id/slider_list"
         android:layout_width="match_parent"
         android:layout_height="match_parent"
         android:background="@android:color/white"
         android:choiceMode="singleChoice"
         android:divider="@android:color/black"
         android:dividerHeight="1dp" />

    </LinearLayout>

the textView will appear just before the sliding menu listview.