public ActionResult Create()
    {
        return View();
    }

    [HttpPost]
    public ActionResult Create(Predbiljezbe predbiljezbePrijava, int id)
    {
        if (ModelState.IsValid)
        {
            string parametarId = RouteData.Values["id"].ToString();

            predbiljezbePrijava.IdSeminara = parametarId;

            context.Predbiljezbes.Add(predbiljezbePrijava);
            context.SaveChanges();

            return RedirectToAction("Index");
        }
        return View(predbiljezbePrijava);
    }

public partial class Predbiljezbe
{
    [System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Usage", "CA2214:DoNotCallOverridableMethodsInConstructors")]
    public Predbiljezbe()
    {
        this.Seminaris = new HashSet<Seminari>();
    }

    public int IdPredbiljezba { get; set; }
    public string Ime { get; set; }
    public string Prezime { get; set; }
    [DataType(DataType.Date)]
    public string Datum { get; set; }
    public string Adresa { get; set; }
    public string Email { get; set; }
    public string Telefon { get; set; }
    public string Status { get; set; }
    public string IdSeminara { get; set; }

    public virtual Seminari Seminari { get; set; }
    [System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Usage", "CA2227:CollectionPropertiesShouldBeReadOnly")]
    public virtual ICollection<Seminari> Seminaris { get; set; }
}

public partial class Seminari
{
    [System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Usage", "CA2214:DoNotCallOverridableMethodsInConstructors")]
    public Seminari()
    {
        this.Predbiljezbes = new HashSet<Predbiljezbe>();
    }

    public string IdSeminar { get; set; }
    public string Naziv { get; set; }
    public string Opis { get; set; }
    [DataType(DataType.Date)]

    public System.DateTime Datum { get; set; }
    public bool Popunjen { get; set; }
    public string Predavač { get; set; }
    public Nullable<int> IdPredbiljezbas { get; set; }
    public Nullable<int> BrojPolaznika { get; set; }

    [System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Usage", "CA2227:CollectionPropertiesShouldBeReadOnly")]
    public virtual ICollection<Predbiljezbe> Predbiljezbes { get; set; }
    public virtual Predbiljezbe Predbiljezbe { get; set; }
}

public partial class SeminariEntities2 : DbContext
{
    public SeminariEntities2()
        : base("name=SeminariEntities2")
    {
    }

    protected override void OnModelCreating(DbModelBuilder modelBuilder)
    {
        throw new UnintentionalCodeFirstException();
    }

    public virtual DbSet<Predbiljezbe> Predbiljezbes { get; set; }
    public virtual DbSet<Seminari> Seminaris { get; set; }
}