Does not exist in current context error

I am using Begining C# although I am fluent in VB6 to get up to speed however I am getting the error "Does not exist in current context"for sqltrans.Rollback.

I have 3 labels and 3 text boxes - textbox1 - 3. It works when I comment the rollback out though. Am I missing something basic or is the code wrong. I could easily code it out and carry on but that would not be helpful later on of course!

Thank you in advance...

 

[code]

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.Data.SqlClient;

namespace WindowsFormsApplication1

{

public partial class Transaction : Form

{

public Transaction()

{

InitializeComponent();

}

private void Form1_Load(object sender, EventArgs e)

{

}

private void button1_Click(object sender, EventArgs e)

{

SqlConnection conn = new SqlConnection(@"

data source = .\sqlexpress;

integrated security = true;

database = Northwind

");

//INSERT statement

string sqlins = @"

insert into customers(customerid,companyname)

values(@newcustid, @newconame) ";

//DELETE statement

string sqldel = @"

delete from customers

where customerid = @oldcustid";

try

{

//open connection

conn.Open();

//begin transaction

SqlTransaction sqltrans = conn.BeginTransaction();

//create insert command

SqlCommand cmdins = conn.CreateCommand();

cmdins.CommandText = sqlins;

cmdins.Transaction = sqltrans;

cmdins.Parameters.Add("@newcustid",

System.Data.SqlDbType.NVarChar, 5);

cmdins.Parameters.Add("@newconame",

System.Data.SqlDbType.NVarChar, 30);

//create delete command

SqlCommand cmddel = conn.CreateCommand();

cmddel.CommandText = sqldel;

cmddel.Transaction = sqltrans;

cmddel.Parameters.Add("@oldcustid",

System.Data.SqlDbType.NVarChar, 5);

//add customer

cmdins.Parameters["@newcustid"].Value = textBox1.Text;

cmdins.Parameters["@newconame"].Value = textBox2.Text;

cmdins.ExecuteNonQuery();

//delete customer

cmddel.Parameters["@oldcustid"].Value = textBox3.Text;

cmddel.ExecuteNonQuery();

//commit transaction

sqltrans.Commit();

//no exception, transaction committed, give message

MessageBox.Show("Transaction committed");

}

catch (System.Data.SqlClient.SqlException ex)

{

//roll back transaction

sqltrans.Rollback();

MessageBox.Show("Transaction rolled back\n" + ex.Message, "Error");

}

finally

{

//close connection

conn.Close();

}

}

private void label1_Click(object sender, EventArgs e)

{

}

}

}

 

 

[/code]