switching between sets of icons in android gridview

Question

I am new to android development. In my android activity I have a GridView and a Button. The GridView adapter class is displaying a set of icons in the GridView. What I want is, if the Button in the activity is clicked, the set of icons in the GridView should be replaced with another set of icons. And every Button click in the activity should switch the two sets of icons in the GridView. So, how to do this using notifyDatasetChanged()? Please Help.

GridView Adapter class:

public class CustomAdapter extends BaseAdapter{

        boolean imageSetChange = false;

        // set 1
        public Integer[] mThumbPics = {
                  R.drawable.pic1, R.drawable.pic2,
                    R.drawable.pic3, R.drawable.pic4,
                    R.drawable.pic5, R.drawable.pic6,
                    R.drawable.pic7, R.drawable.pic8,
                    R.drawable.pic9, R.drawable.pic10,
                    R.drawable.pic11, R.drawable.pic12,
                    R.drawable.pic13, R.drawable.pic14,
                    R.drawable.pic15, R.drawable.pic16,
                    R.drawable.pic17, R.drawable.pic18,
                    R.drawable.pic19, R.drawable.pic20,
                    R.drawable.pic21

        };
        //set 2
        public Integer[] mThumbEng = {
                R.drawable.eng_pic1, R.drawable.eng_pic2,
                R.drawable.eng_pic3, R.drawable.eng_pic4,
                R.drawable.eng_pic5, R.drawable.eng_pic6,
                R.drawable.eng_pic7, R.drawable.eng_pic8,
                R.drawable.eng_pic9, R.drawable.eng_pic10,
                R.drawable.eng_pic11, R.drawable.eng_pic12,
                R.drawable.eng_pic13, R.drawable.eng_pic14,
                R.drawable.eng_pic15, R.drawable.eng_pic16,
                R.drawable.eng_pic17, R.drawable.eng_pic18,
                R.drawable.eng_pic19, R.drawable.eng_pic20,
                R.drawable.eng_pic21
               };

        private Context mContext;
        View MyView;
        ImageView imageView;

        public CustomAdapter(Context c){
            mContext = c;
        }

        @Override
        public int getCount() {
            // TODO Auto-generated method stub
            return mThumbEng.length;
        }

        @Override
        public Object getItem(int position) {
            // TODO Auto-generated method stub
            return mThumbEng[position];
        }

        @Override
        public long getItemId(int position) {
            // TODO Auto-generated method stub
            return 0;
        }

        @Override
        public View getView(int position, View convertView, ViewGroup parent) {
            // TODO Auto-generated method stub
            if(imageSetChange==false)
            {if(convertView == null){

                    LayoutInflater li=((Activity) mContext).getLayoutInflater();
                    MyView=li.inflate(R.layout.menuitem, null);

                    }
                    else{
                        MyView=(View)convertView;
                    }
                imageView =(ImageView)MyView.findViewById(R.id.image);

                imageView.setImageResource(mThumbEng[position]);

                       return MyView;
                       }
            else{

                if(convertView == null){

                    LayoutInflater li=((Activity) mContext).getLayoutInflater();
                    MyView=li.inflate(R.layout.menuitem, null);

                    }
                    else{
                        MyView=(View)convertView;
                    }
                imageView =(ImageView)MyView.findViewById(R.id.image);

                imageView.setImageResource(mThumbUrdu[position]);

                       return MyView;


            }


        }   

        /** public void changeImages(boolean change){
            this.imageSetChange  = change;

            cda.notifyDataSetChanged();

        }
    **/

}

Button onclick listener:

Button lang_change_btn = (Button) findViewById(R.id.button1);
        lang_change_btn.setOnClickListener(new OnClickListener() {

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

                //cda.changeImages(true);


            }
        });