private void AddNannyClick(object sender, RoutedEventArgs e)
        {
            string tmp      = "";
            int    count_ec = 0;

            try
            {
                bool check1 = first_NameTextBox.Text.Any(who => char.IsLetter(who));
                if (first_NameTextBox.Text != null)
                {
                    if (!check1)
                    {
                        first_NameTextBox.BorderBrush = Brushes.Red;
                        tmp += "Invalid First name! \n";
                        first_NameTextBox.Text = "";
                        count_ec++;
                    }
                }

                bool check2 = first_NameTextBox.Text.Any(who => char.IsLetter(who));
                if (last_NameTextBox.Text != null)
                {
                    if (!check2)
                    {
                        last_NameTextBox.BorderBrush = Brushes.Red;
                        tmp += "Invalid Last name! \n";
                        last_NameTextBox.Text = "";
                        count_ec++;
                    }
                }

                if ((iDTextBox.Text != null) && (iDTextBox.Text != "0"))
                {
                    if (typeof(int) != (Convert.ToInt32(iDTextBox.Text).GetType()))
                    {
                        iDTextBox.BorderBrush = Brushes.Red;
                        tmp           += "Invalid ID Number! \n";
                        iDTextBox.Text = "";
                        count_ec++;
                    }
                }
                if (addressTextBox.Text != null)
                {
                    if (typeof(string) != (addressTextBox.Text.GetType()))
                    {
                        addressTextBox.BorderBrush = Brushes.Red;
                        tmp += "Invalid Address! \n";
                        addressTextBox.Text = "";
                        count_ec++;
                    }
                }

                if (phone_NumberTextBox.Text != null)
                {
                    if ((typeof(int) != (Convert.ToInt32(phone_NumberTextBox.Text).GetType())))
                    {
                        phone_NumberTextBox.BorderBrush = Brushes.Red;
                        tmp += "Invalid Phone Number! \n";
                        phone_NumberTextBox.Text = "";
                        count_ec++;
                    }
                }
                if (floorTextBox.Text != null)
                {
                    if ((typeof(int) != (Convert.ToInt32(floorTextBox.Text).GetType())))
                    {
                        floorTextBox.BorderBrush = Brushes.Red;
                        tmp += "Invalid Value For Floor! \n";
                        floorTextBox.Text = "";
                        count_ec++;
                    }
                }
                if (max_ChildsTextBox.Text != null)
                {
                    if ((typeof(int) != (Convert.ToInt32(max_ChildsTextBox.Text).GetType())))
                    {
                        max_ChildsTextBox.BorderBrush = Brushes.Red;
                        tmp += "Invalid Value For Maximum Of Child! (integer) \n";
                        max_ChildsTextBox.Text = "";
                        count_ec++;
                    }
                }
                if (min_AgeTextBox.Text != null)
                {
                    if ((typeof(int) != (Convert.ToInt32(min_AgeTextBox.Text).GetType())) || ((Convert.ToInt32(min_AgeTextBox.Text)) > (Convert.ToInt32(max_AgeTextBox.Text))))
                    {
                        min_AgeTextBox.BorderBrush = Brushes.Red;
                        tmp += "Invalid Value For Minimum Age Of Child! (integer) \n";
                        min_AgeTextBox.Text = "";
                        count_ec++;
                    }
                }
                if (max_AgeTextBox.Text != null)
                {
                    if ((typeof(int) != (Convert.ToInt32(max_AgeTextBox.Text).GetType())))
                    {
                        max_AgeTextBox.BorderBrush = Brushes.Red;
                        tmp += "Invalid Value For Maximum Age Of Child! (integer) \n";
                        max_AgeTextBox.Text = "";
                        count_ec++;
                    }
                }
                if (experienceTextBox.Text != null)
                {
                    if ((typeof(int) != (Convert.ToInt32(experienceTextBox.Text).GetType())))
                    {
                        experienceTextBox.BorderBrush = Brushes.Red;
                        tmp += "Invalid Value For Experience Of Nanny! (integer) \n";
                        experienceTextBox.Text = "";
                        count_ec++;
                    }
                }

                if ((DateTime)dateDatePicker.SelectedDate >= (DateTime.Today))
                {
                    tmp += "Invalid Date!";
                    count_ec++;
                }

                if ((pay_For_HourTextBox.Text != null) && (pay_For_HourTextBox.Text != "0"))
                {
                    if (typeof(double) != ((double)(Convert.ToInt32(pay_For_HourTextBox.Text))).GetType())
                    {
                        pay_For_HourTextBox.BorderBrush = Brushes.Red;
                        tmp += "Invalid Pay! \n";
                        pay_For_HourTextBox.Text = "";
                        count_ec++;
                    }
                }
                if ((pay_For_MountTextBox.Text != null) && (pay_For_MountTextBox.Text != "0"))
                {
                    if (typeof(double) != ((double)(Convert.ToInt32(pay_For_MountTextBox.Text))).GetType())
                    {
                        pay_For_MountTextBox.BorderBrush = Brushes.Red;
                        tmp += "Invalid Pay! \n";
                        pay_For_MountTextBox.Text = "";
                        count_ec++;
                    }
                }

                if (Convert.ToInt32(max_AgeTextBox.Text) > Convert.ToInt32(min_AgeTextBox.Text))
                {
                    tmp += "Max age > Min age \n";
                    max_AgeTextBox.BorderBrush = Brushes.Red;
                    min_AgeTextBox.BorderBrush = Brushes.Red;
                    count_ec++;
                }

                //check if selected hours
                bool flag = false;
                foreach (var item in nanny.Work_Hours)
                {
                    if (item[0] != 0 && item[1] != 0)
                    {
                        flag = true;
                    }
                }
                if (!flag)
                {
                    tmp += "No hours selected \n";
                    count_ec++;
                }
                //check if hours(begin <end) ok
                flag = true;
                foreach (var item in nanny.Work_Hours)
                {
                    if (item[0] > item[1])
                    {
                        flag = false;
                    }
                }
                if (!flag)
                {
                    tmp += "Start time is less than end time\n";
                    count_ec++;
                }


                if (count_ec != 0)
                {
                    throw new Exception(tmp);
                }
                else
                {
                    bl.Add_Nanny(nanny);
                    MessageBox.Show("Add Nanny successful");
                    nanny            = new BE.Nanny();
                    this.DataContext = nanny;
                    Close();
                }
            }
            catch (Exception ex)
            {
                MessageBox.Show(ex.Message);
            }
        }