I want tack exam with android , and i create with check box , now how can i tack exam and check true answer

how can check answers ? i have error with this method

public class exam_1_program extends Activity {

private ListView listview;
private CheckBox check1;
private CheckBox check2;
private CheckBox check3;
private CheckBox check4;

public static final String[] Queshion_txt = new String[] { "سوال 1",
        "سوال 2", "سوال 3", "سوال 4", "سوال 5" };

public static final String[] check_itam_1 = new String[] { "تست یک",
        "تست یک سوال دو",

        "تست یک سوال سه ", "تست یک سوال چهار", "تست یک سوال پنج"

};

public static final String[] check_itam_2 = new String[] { "تست دو",
        "تست دو سوال دو", "تست دو سوال سه", "تست دو سوال چهار",
        "تست دو سوال پنج"

};

public static final String[] check_itam_3 = new String[] { "تست سه",
        "تست دو سال سه", "تست سه سوال سه", "تست چهار سوال سه",
        "تست پنج سوال سه"

};

public static final String[] check_itam_4 = new String[] { "تست چهار",
        "تست دو سوال چهار", "سوال سه", "سوال چهار", "سوال پنج"

};

List<itam_row_adapter_exam> rowItems;

protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.exam_1);

    check1 = (CheckBox) findViewById(R.id.item_1);
    check2 = (CheckBox) findViewById(R.id.item_2);
    check3 = (CheckBox) findViewById(R.id.item_3);
    check4 = (CheckBox) findViewById(R.id.item_4);

    rowItems = new ArrayList<itam_row_adapter_exam>();

    for (int i = 0; i < Queshion_txt.length; i++) {
        itam_row_adapter_exam item = new itam_row_adapter_exam(
                Queshion_txt[i], check_itam_1[i], check_itam_2[i],
                check_itam_3[i], check_itam_4[i]);
        rowItems.add(item);
    }

    listview = (ListView) findViewById(R.id.listview_exam);
    BaseAdapter_exam adapter = new BaseAdapter_exam(this, rowItems);
    listview.setAdapter(adapter);

    check1.setOnClickListener(new OnClickListener() {

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

            if (((CheckBox) v).isChecked()) {
                Toast.makeText(getApplicationContext(),"Bro, try Android :)", Toast.LENGTH_LONG).show();
            }

        }

    });

    // if (check1) {
    //
    // Toast.makeText(getApplicationContext(),"This is an Android Toast Message",
    // Toast.LENGTH_LONG).show();
    //
    // }

}

}

public class BaseAdapter_exam extends BaseAdapter {

Context context;
private List<itam_row_adapter_exam> rowItems;

public BaseAdapter_exam(Context context, List<itam_row_adapter_exam> items) {

    this.context = context;
    this.rowItems = items;
}

private class ViewHolder_exam {

    TextView txtQueshion;
    CheckBox check1;
    CheckBox check2;
    CheckBox check3;
    CheckBox check4;
}


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

@Override
public Object getItem(int position) {
    // TODO Auto-generated method stub
    return rowItems.get(position);
}

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

@Override
public View getView(int position, View convertView, ViewGroup parent) {
    ViewHolder_exam holder = null;
    LayoutInflater mInflater = (LayoutInflater) context
            .getSystemService(Activity.LAYOUT_INFLATER_SERVICE);
    if (convertView == null) 
    {

            convertView = mInflater.inflate(R.layout.question, null);
            holder = new ViewHolder_exam();
            holder.txtQueshion = (TextView) convertView.findViewById(R.id.textView1);
            holder.check1 = (CheckBox) convertView.findViewById(R.id.item_1);
            holder.check2 = (CheckBox) convertView.findViewById(R.id.item_2);
            holder.check3 = (CheckBox) convertView.findViewById(R.id.item_3);
            holder.check4 = (CheckBox) convertView.findViewById(R.id.item_4);

            convertView.setTag(holder);
        } else
        {
            holder = (ViewHolder_exam) convertView.getTag();
        }
        itam_row_adapter_exam rowItem = (itam_row_adapter_exam) getItem(position);

        holder.txtQueshion.setText(rowItem.getquetion());
        holder.check1.setText(rowItem.getcheck1());
        holder.check2.setText(rowItem.getcheck2());
        holder.check3.setText(rowItem.getcheck3());
        holder.check4.setText(rowItem.getcheck4());

    return convertView;
}

}

package adapter_view;

public class itam_row_adapter_exam {

private String quetion = "";
private String check1 = "";
private String check2 = "";
private String check3 = "";
private String check4 = "";

public itam_row_adapter_exam(String quetion, String check1, String check2,
        String check3, String check4) {

    this.quetion = quetion;
    this.check1 = check1;
    this.check2 = check2;
    this.check3 = check3;
    this.check4 = check4;

}

//
public String getquetion() {
    return quetion;

}

public void setquetion(String quetion) {
    this.quetion = quetion;

}

//
public String getcheck1() {
    return check1;

}

public void setchechk1(String check1) {
    this.check1 = check1;

}

//
public String getcheck2() {
    return check2;

}

public void setchechk2(String check2) {
    this.check2 = check2;

}

//
public String getcheck3() {
    return check3;

}

public void setchechk3(String check3) {
    this.check3 = check3;

}

//
public String getcheck4() {
    return check4;

}

public void setchechk4(String check4) {
    this.check4 = check4;

}
//

}