public bool DeleteEmployee(Employee employee)
        {
            var selectedEmployee = Db.Employees.Find(employee.Id);
            Db.Entry(selectedEmployee).State = System.Data.Entity.EntityState.Deleted;

            return SaveDbChanges();
        }
 public bool Save(Employee employee)
 {
     if (employee.Id <= 0)
     {
         Db.Employees.Add(employee);
     }
     else
     {
         Db.Employees.Attach(employee);
         Db.Entry(employee).State = EntityState.Modified;
     }
     return SaveDbChanges();
 }