i try to use transaction in Entity FrameWork. i have 3 tables Personel, Prim, Finans. in Prim table you look SatisTutari (int) if i add data in SatisTutari.Text instead of int value adding float value. Trannsaction must be run! Everything is ok but how can i refactoring or give best performance or best writing Transaction coding!

i have 3 table so i have 3 entities:

CREATE TABLE Personel 
(PersonelID integer PRIMARY KEY identity not null, 
Ad varchar(30), 
Soyad varchar(30),
Meslek varchar(100),
DogumTarihi datetime,
DogumYeri nvarchar(100),
PirimToplami float);

Go

create TABLE Prim
(PrimID integer PRIMARY KEY identity not null,
PersonelID integer Foreign KEY references Personel(PersonelID),
SatisTutari int,
Prim float,
SatisTarihi Datetime);

Go

CREATE TABLE Finans 
(ID integer PRIMARY KEY identity not null, 
Tutar float);

Personel, Prim,Finans my tables. if you look Prim table you can see Prim value float value if i write a textbox not float value my transaction must run.

   protected void btnSave_Click(object sender, EventArgs e)
        {
            using (TestEntities testCtx = new TestEntities())
            {
                using (TransactionScope scope = new TransactionScope())
                {
                    Personel personel = new Personel();
                    Prim prim = new Prim();
                    Finans finans = new Finans();
                    //-----------------------------------------------------------------------Step 1
                    personel.Ad = txtName.Text;
                    personel.Soyad = txtSurName.Text;
                    personel.Meslek = txtMeslek.Text;
                    personel.DogumTarihi = DateTime.Parse(txtSatisTarihi.Text);
                    personel.DogumYeri = txtDogumYeri.Text;
                    personel.PirimToplami = float.Parse(txtPrimToplami.Text);
                    testCtx.AddToPersonel(personel);
                    testCtx.SaveChanges();
                    //----------------------------------------------------------------------- step 2

                    prim.PersonelID = personel.PersonelID;
                    prim.SatisTutari = int.Parse(txtSatisTutari.Text);
                    prim.SatisTarihi = DateTime.Parse(txtSatisTarihi.Text);
                    prim.Prim1 = double.Parse(txtPrim.Text); 
                    finans.Tutar = prim.SatisTutari * prim.Prim1;
                    testCtx.AddToPrim(prim);
                    testCtx.SaveChanges();
                   //----------------------------------------------------------------------- step 3

                    lblTutar.Text = finans.Tutar.Value.ToString();
                    testCtx.AddToFinans(finans);
                    testCtx.SaveChanges();

                    scope.Complete();
                }
            }

How can i rearrange codes. i need best practice refactoring and best solution for reading easly and performance!!!