Creating a derived object from an existing base object in .net

Dumb question.

Lets say I have a bunch of person objects with their fields all filled in with data and I have an employee type that derives from the person class and has extra fields related to being an employee. How do I get a employee object for a particular existing person object? i.e. How do I pass in the person object to the employee?

From stackoverflow

• If the person was created as an employee, then just cast:

  Person person = new Employee(); // for some reason
  ...
  Employee emp = (Employee)person;
  

  If the person is just a person: you can't; you could have the employee encapsulate the Person - or you can copy the fields:

  class Employee { // encapsulation
    private readonly Person person;
    public Person {get {return person;}}
    public Employee(Person person) {this.person = person;}
    public Employee() : this(new Person()) {}
  }
  

  or

  class Employee : Person { // inheritance
    public Employee(Person person) : base(person) {}
    public Employee() {}
  }
  class Person {
      public Person(Person template) {
          this.Name = template.Name; // etc
      }
      public Person() {}
  }
  

  Christopher Edwards : I thought as much; thanks for the answer.