/// <summary>
/// Loads a Person from the database.
/// Precondition: Must not be editing.
/// Precondition: Must be new.
/// Postcondition: Object is in a valid state.
/// </summary>
public void Load(string socialSecurityNumber)
{
Trace.Assert(!isEditing, "Must not be editing.");
Trace.Assert(isNew, "Must be new.");
// Load the object
PersonManager manager = new PersonManager();
PersonProperties properties = manager.Load(socialSecurityNumber);
Trace.Assert(properties.IsPopulated, "Person must have all its properties set.");
this.SetState(properties);
isNew = false;
Trace.Assert(IsValid, "Should be valid.");
}