Soap Header WCF

Hi, i have a service in which SOAP Header Attribute is used for passing paramters.

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.Services;
using System.Web.Services.Protocols;

[WebService(Namespace = "S:Apple.Summry")]
[WebServiceBinding(ConformsTo = WsiProfiles.BasicProfile1_1)]
// To allow this Web Service to be called from script, using ASP.NET AJAX, uncomment the following line. 
// [System.Web.Script.Services.ScriptService]

public class Service : System.Web.Services.WebService
{
    public class Apple : SoapHeader
    {
        public string Amountt = "0.0";
        public string Number = "1";
        public string Type = "Credit";
        public string Date = "2011/09/26";
        public string Id = "AVST000XXXX201109990000012";
    }
	
    public Service () {

        //Uncomment the following line if using designed components 
        //InitializeComponent(); 
    }
    public Apple apple;

    [WebMethod]
    [SoapHeader("apple", Direction = SoapHeaderDirection.InOut)]
    public void HelloWorld() 
    {
        if (apple == null) { apple = new Apple(); }
    }
}

but now i need do this work in a wcf service

Please help how do i use Soap Header in WCF, its really urgent please help me......