Base de bonne sql sous visual studio c#

voici mon script:
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using System.Configuration;
using System.Data.SqlServerCe;



namespace RENTAL
{
public partial class Form1 : Form
{
Form2 F2 = new Form2();
public Form1()
{
InitializeComponent();
}

private void Rental_Click(object sender, EventArgs e)
{
panel1.Visible = true;
panel2.Visible = true;
panel3.Visible = false;
}

private void panel1_Paint(object sender, PaintEventArgs e)
{
civ.Items.Clear();
nam.Text = "";
fir.Text = "";
com.Items.Clear();
roo.Text = "";
id.Text = "";
pty.Items.Clear();
gen.Items.Clear();
tit.Items.Clear();


civ.Items.AddRange(new object[] {"Madame", "Mademoiselle", "Monsieur" });
com.Items.AddRange(new object[] {"CIS", "SNC LAVALIN", "SHERRITT", "HENRI FRAISE" });


}
private void Form1_Load(object sender, EventArgs e)
{

}

private void Cancel_Click(object sender, EventArgs e)
{
civ.Items.Clear();
nam.Text = "";
fir.Text = "";
com.Items.Clear();
roo.Text="";
id.Text="";
pty.Items.Clear();
gen.Items.Clear();
tit.Items.Clear();

}

private void Save_Click(object sender, EventArgs e)
{

SqlCeConnection connexion = new SqlCeConnection(connectionString);
{
// ouverture connexion
connexion.Open();
// configuration commande
// insertion dans la table Personnes
string requête = "insert into Personnes(CIVILITES,NAME,FIRSTNAME,COMPANY,ROOM,ID)" +
values(@civ, @nam, @fir, @com, @roo, @id);
SqlCeCommand sqlCommand = new SqlCeCommand(requête, connexion);
sqlCommand.Parameters.Add("@civ", SqlDbType.NVarChar, 10);
sqlCommand.Parameters.Add("@nam", SqlDbType.NVarChar, 20);
sqlCommand.Parameters.Add("@fir", SqlDbType.NVarChar, 20);
sqlCommand.Parameters.Add("@com", SqlDbType.NVarChar, 10);
sqlCommand.Parameters.Add("@roo", SqlDbType.Int);
sqlCommand.Parameters.Add("@id", SqlDbType.Int);
// compilation de la commande
sqlCommand.Prepare();

// insertion dans la table Produits
string requête2 = "insert into Produits(Type_Produits,Genre_Produits,Title_Produits)" +
values(@pty, @gen, @tit);
SqlCeCommand sqlCommand2 = new SqlCeCommand(requête2, connexion);
sqlCommand.Parameters.Add("@pty", SqlDbType.NVarChar, 10);
sqlCommand.Parameters.Add("@gen", SqlDbType.NVarChar, 10);
sqlCommand.Parameters.Add("@tit", SqlDbType.NVarChar, 200);
// compilation de la commande
sqlCommand.Prepare();
}
}

private void Sitting_Click(object sender, EventArgs e)
{
panel3.Visible = true;
panel1.Visible = false;
panel2.Visible = false;
}

private void panel3_Paint(object sender, PaintEventArgs e)
{
typ.Items.Clear();
gen2.Items.Clear();
tit2.Text = "";

typ.Items.AddRange(new object[] { "DVD", "BOOK", "PS3" });
if (typ.Text == "DVD")
{

gen2.Items.AddRange(new object[] {"","ARMATIAL",
"DRAMATIQUE",
"",
"SENTIMENTAL",
"ACTION",
"COMEDI"});

//tit2.Items.Clear();
//tit2.Items.AddRange(new object[] { });

}

if (typ.Text == "BOOK")
{

gen2.Items.AddRange(new object[] {"","CHINESSE",
"KOREAN",
"CARTOON"});

//tit2.Items.Clear();
//tit2.Items.AddRange(new object[] { });
}
}

private void panel2_Paint(object sender, PaintEventArgs e)
{
pty.Items.AddRange(new object[] { "DVD", "BOOK", "PS3" });

if (pty.Text == "DVD")
{

gen.Items.AddRange(new object[] {"","ARMATIAL",
"DRAMATIQUE",
"",
"SENTIMENTAL",
"ACTION",
"COMEDI"});

//tit.Items.Clear();
//tit.Items.AddRange(new object[] { });

}

if (pty.Text == "BOOK")
{

gen.Items.AddRange(new object[] {"","CHINESSE",
"KOREAN",
"CARTOON"});

//tit.Items.Clear();
//tit.Items.AddRange(new object[] { });
}
}

private void add_Click(object sender, EventArgs e)
{
SqlCeConnection connexion = new SqlCeConnection(connectionString);
{
// ouverture connexion
connexion.Open();
// configuration commande
string requête = "insert into Produits(Type_Produits,Genre_Produits,Title_Produits)" +
values (@typ, @gen2, @tit2);
SqlCeCommand sqlCommand = new SqlCeCommand(requête, connexion);
sqlCommand.Parameters.Add("@typ", SqlDbType.NVarChar, 10);
sqlCommand.Parameters.Add("@gen2", SqlDbType.NVarChar, 10);
sqlCommand.Parameters.Add("@tit2", SqlDbType.NVarChar, 200);

// compilation de la commande
sqlCommand.Prepare();
}
}

}
}
commentaire: sous une bouton save et add, je veux enregistrer et ajouter des donnés.
merci!