Create Appointment in Appointment

function create_appointment(id){
    //myID
    var myId = frames[1].Xrm.Page.data.entity.getId();
    //Create the activityparty
    activityparty myParty = new activityparty();
    myParty.partyid = CrmTypes.CreateLookup(EntityName.systemuser.ToString(), myId);
    //Create the appointment Object 
    appointment myAppointment = new appointment();
    //Set the appointment Object's properties 
    myAppointment.description = "description";
    myAppointment.ownerid = CrmTypes.CreateOwner(EntityName.systemuser.ToString(), myId);
    myAppointment.scheduledstart = DateTime.Now.AddHours(1);
    myAppointment.scheduledend = DateTime.Now.AddHours(2);
    myAppointment.location = "location";
    myAppointment.subject = "subject";
    myAppointment.regardingobjectid = id;
    //Create the Target  
    TargetScheduleAppointment myAppointmentTarget = new TargetScheduleAppointment();
    //Set the Target's Properties 
    myAppointmentTarget.Appointment = myAppointment;
    //Create the Request Object 
    BookRequest myBookRequest = new BookRequest();
    //Set the Request Object's Properties 
    myBookRequest.Target = myAppointmentTarget;
    //Execute the Request 
    BookResponse booked = (BookResponse) myService.Execute(myBookRequest);
}

lookup = Xrm.Page.getAttribute("regardingobjectid").getValue();
    if (lookup != null) {
        var name = lookup[0].name;
        var id = lookup[0].id;
        var entityType = lookup[0].entityType;
    }