Unity constructor options

class Entity:IEntityName
{
    #region IEntityName Members

    public string FirstName { get; set; }
    public string LastName { get; set; }
    #endregion
}

public class Person:IPerson
{
    public IEntityName EntityName;

    public Person()
    {
    }

    public Person(IEntityName EntityName)
    {
        this.EntityName = EntityName;
    }

    public string ReverseName()
    {
        return string.Format("Your reverse name is {0} {1}",EntityName.LastName, EntityName.FirstName);
    }

    public override string ToString()
    {
        return string.Format("Name is {0} {1}", EntityName.FirstName, EntityName.LastName);
    }
}

// Main Method

private static string DisplayReverseName(string fName,string lName)
{
        IUnityContainer container = new UnityContainer();
        container.RegisterType<IPerson, Person>().RegisterType<IEntityName,Entity>();

        IEntityName entityName = container.Resolve<IEntityName>();

        entityName.FirstName = fName;
        entityName.LastName = lName;
        var p = container.Resolve<IPerson>(); 
        return p.ReverseName(); //  firstName and lastName are still null
    }

      

        
        
        
      

    

How can I insert the constructor firstName and lastName into Person?