user must be logged in after created.

 Hello.
I present registeration page using membership provider. I want user be logged in if create user status is success. here is my codes:
 
        string kullanici_adi = TextBox1.Text;
        string sifre = TextBox2.Text;
        string email = TextBox3.Text;
        string sifresorusu = TextBox4.Text;
        string sifrecevabi = TextBox5.Text;
        MembershipCreateStatus uye_olusturma_sonuc;

        Membership.CreateUser(kullanici_adi, sifre, email, sifresorusu, sifrecevabi, true, out uye_olusturma_sonuc);

       
        if (uye_olusturma_sonuc == MembershipCreateStatus.Success)< ...