/// <summary>
 /// This method invokes a methods for editing employee achecks if sector of employee exists. If not exist, invokes a method for adding sector.
 /// </summary>
 public void SaveExecute()
 {
     if (String.IsNullOrEmpty(Employee.NameAndSurname) || String.IsNullOrEmpty(Employee.NumberOfIdentityCard) || String.IsNullOrEmpty(Employee.JMBG) || Gender == null ||
         String.IsNullOrEmpty(Employee.PhoneNumber) || String.IsNullOrEmpty(Sector) || Location == null)
     {
         MessageBox.Show("Please fill all fields.", "Notification");
     }
     else
     {
         try
         {
             MessageBoxResult result = MessageBox.Show("Are you sure you want to save the changes?", "Confirmation", MessageBoxButton.YesNo, MessageBoxImage.Question);
             if (result == MessageBoxResult.Yes)
             {
                 if (sectors.IsSectorExists(Sector) == false)
                 {
                     sectors.AddSector(sector);
                 }
                 //invoking method to find sector and setting that sector to employee sector
                 Employee.Sector     = sectors.FindSector(sector);
                 Employee.LocationId = Convert.ToInt32(Location.LocationId);
                 Employee.Gender     = Convert.ToInt32(Gender.GenderId);
                 if (Manager != null)
                 {
                     Employee.Manager = Convert.ToInt32(Manager.EmployeeId);
                 }
                 bool isEdited = employees.EditEmployee(Employee);
                 if (isEdited)
                 {
                     MessageBox.Show("Employee is edited.", "Notification", MessageBoxButton.OK);
                     sectors.DeleteSector(OldEmployee.SectorName);
                     editEmployeeView.Close();
                 }
                 else
                 {
                     MessageBox.Show("Employee cannot be edited.", "Notification", MessageBoxButton.OK);
                 }
             }
         }
         catch (Exception ex)
         {
             MessageBox.Show(ex.ToString());
         }
     }
 }