I have created an app which shows around 40 qoutes by pressing next button

I have created an app which shows around 40 qoutes by pressing next button but now I want my PREV button to be functional & I'm not getting it's way as I'm new to android. Below is my app code:

Main Activity:

package com.example.i7.fun_quotes;

import android.graphics.Color; import android.support.v7.app.AppCompatActivity; import android.os.Bundle; import android.text.style.BackgroundColorSpan; import android.util.Log; import android.view.View; import android.widget.Button; import android.widget.RelativeLayout; import android.widget.TextView; import android.widget.Toast;

import java.util.Random;

public class MainActivity extends AppCompatActivity { public static final String TAG = "FunFactActivity"; private FunObject mFunObject = new FunObject(); private TextView mFunTextView; private Button mFunButtonView; //private Button mPrevbutton; private RelativeLayout mRelativeLayout; private FunColor mFunColor = new FunColor();

@Override
protected void onCreate(Bundle savedInstanceState) {



    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    mFunTextView = (TextView) findViewById(R.id.FunTextView);
    mFunButtonView = (Button) findViewById(R.id.FunButtonView);
   // mPrevbutton = (Button) findViewById(R.id.Prevbutton);
    mRelativeLayout= (RelativeLayout) findViewById(R.id.Relativelayout);


    View.OnClickListener Listner = new View.OnClickListener(){

        @Override
        public void onClick(View v) {

            String fact = mFunObject.GetFact();
            int colorAsInt = mFunColor.GetColor();

            mFunTextView.setText(fact);
            mRelativeLayout.setBackgroundColor(colorAsInt);

        }
    };

    mFunButtonView.setOnClickListener(Listner);
    //mPrevbutton.setOnClickListener();

// Toast.makeText(MainActivity.this, "MY FUN FACTS APP", Toast.LENGTH_SHORT).show(); Log.d("TAG","I'm standing here");

}

}