Select query keeps crashing my application

I am trying to implement this select query in my application but it keeps crashing my app.

  public ArrayList getSelectedContacts(String name)
      {
       ArrayList array_list = new ArrayList();
       SQLiteDatabase db = this.getReadableDatabase();
       Cursor res = db.rawQuery("select * from contacts where name = ?",new String[]{name});
       res.moveToFirst();
       while(res.isAfterLast() == false)
            {
            array_list.add(res.getString(res.getColumnIndex(CONTACTS_COLUMN_NAME)));
            res.moveToNext();
            }
    return array_list;
    }