private void OKButton_Click(object sender, RoutedEventArgs e)
        {
            SQLQuery mSqlQuery = new SQLQuery();

            if (checkSalary() && roomID.SelectedIndex > -1)
            {
                int numOFRoom = int.Parse(roomID.Text.ToString());
                mSqlQuery.updateRoomData(new Room(getRoomID[numOFRoom], numOFRoom, Int64.Parse(ID.Text)));
                mSqlQuery.updateStaffData(GlobalVariables.globalStaff);
            }
            else
            {
                MessageBox.Show("Please Enter the Room number", "Invaild Data", MessageBoxButton.OK, MessageBoxImage.Error);
            }
        }