SQL Multiple Update Statements that will affect two tables

Well done!
+5!

It is still not working for me - I found an error however when I debugged the procedure. It seems for some reason that although I enter just one password into the txtOldPassword field it seems to double it when it is passed into the procedure??

Here is my Page Load code that fills the textboxes with data from the logged in user from the database.

protected void Page_Load(object sender, EventArgs e)
{
Label1.Text = "Welcome " + Session["User"];
lblUser.Text = Convert.ToString(Session["User"]);

SqlConnection conn;
SqlCommand comm;
String connectionString = ConfigurationManager.ConnectionStrings["ApplicationServices"].ConnectionString;

conn = new SqlConnection(connectionString);
comm = new SqlCommand("SELECT * from Business a, User_Acc c Where c.Username = @Username AND c.Business_ID = a.Business_ID", conn);
comm.Parameters.Add("@Username", System.Data.SqlDbType.VarChar).Value = Session["User"];
conn.Open();
SqlDataReader reader = comm.ExecuteReader();
while (reader.Read())
{

txtChangeBusinessName.Text += reader["Business_Name"];
txtChangeBusinessAddress.Text += reader["Address_Line_1"];
txtChangeBusinessAddress2.Text += reader["Address_Line_2"];
txtChangeBusinessAddress3.Text += reader["Address_Line_3"];
DDLProvince.SelectedItem.Text = "";
DDLCounty.SelectedItem.Text = "";
DDLProvince.SelectedItem.Text += reader["Provence"];
DDLCounty.SelectedItem.Text += reader["County"];
lblVatNo.Text += reader["Vat_No"];
txtChangeBusinessEmail.Text += reader["Email"];
txtChangeBusinessTelephone.Text += reader["Telephone"];
txtOldPassword.Text += reader["Password"];
txtChangeBusinessPassword.Text += reader["Password"];

}


reader.Close();
conn.Close();

}

If I change txtChangeBusinessName.text to = rather than += I get an error :

cannot implicitly convert type 'object' to 'string'. an explicit conversion exists.

I have the error :

cannot implicitly convert type 'string' to 'bool'

here is the line of code

if (txtOldPassword.Text = reader["Password"].ToString())

I have updated my code and it now runs - however when I make changes to any textboxes on the webpage and click the button to run the procedure, it doesn't take in the updated values but rather the values from the other data reader

protected void SaveChanges(object sender, EventArgs e)
{
SqlConnection conn;
SqlCommand comm;
String connectionString = ConfigurationManager.ConnectionStrings["ApplicationServices"].ConnectionString;
conn = new SqlConnection(connectionString);
comm = new SqlCommand("SELECT * from Business a, User_Acc c Where c.Username = @Username AND c.Business_ID = a.Business_ID", conn);
comm.Parameters.Add("@Username", System.Data.SqlDbType.VarChar).Value = Session["User"];
conn.Open();
SqlDataReader reader = comm.ExecuteReader();
while (reader.Read())
{
if (txtOldPassword.Text == reader["Password"].ToString())
{
// I'm not confortable using the same connection as the read - especially as we appear to
// be inside a reader loop so I'll create a new connection for the stored proc update
SqlConnection connWrite;
connWrite = new SqlConnection(connectionString);
// For info on the using statement see http://msdn.microsoft.com/en-us/library/htd05whh.aspx
using (SqlCommand comm1 = new SqlCommand("exec SaveBusinessChanges @Business_Name,@Address_Line_1,@Address_Line_2,@Address_Line_3,@County,@Provence,@Telephone,@Username,@PasswordNew,@Email", connWrite))
{
// Let the command know it is to run a Stored Procedure
comm1.CommandType = CommandType.StoredProcedure;
// This bit unchanged from OPs code
comm1.Parameters.AddWithValue("@Business_Name", txtChangeBusinessName.Text);
comm1.Parameters.AddWithValue("@Email", txtChangeBusinessEmail.Text);
comm1.Parameters.AddWithValue("@Telephone", txtChangeBusinessTelephone.Text);
comm1.Parameters.AddWithValue("@Address_Line_1", txtChangeBusinessAddress.Text);
comm1.Parameters.AddWithValue("@Address_Line_2", txtChangeBusinessAddress2.Text);
comm1.Parameters.AddWithValue("@Address_Line_3", txtChangeBusinessAddress3.Text);
comm1.Parameters.AddWithValue("@Provence", DDLProvince.Text);
comm1.Parameters.AddWithValue("@County", DDLCounty.Text);
comm1.Parameters.AddWithValue("@Username", Session["User"]);
comm1.Parameters.AddWithValue("@PasswordNew", txtChangeBusinessPassword.Text);
// You need to execute the command to run the stored procedure
comm1.ExecuteNonQuery();
} // Because I've used a "using" statement I don't need connWrite.Close();
}
}
reader.Close();
conn.Close();

Response.Redirect("Welcome.aspx");
}
}

I now have the updated textbox values being passed to the parameter in my c# code but when I am redirected back to business details page the updated details are not there so maybe there is a problem with updating two tables in my proc???

ALTER PROCEDURE dbo.SaveBusinessChanges
(
@Business_Name varchar(50),
@Address_Line_1 varchar(50),
@Address_Line_2 varchar(50),
@Address_Line_3 varchar(50),
@County varchar(50),
@Provence varchar(50),
@Telephone varchar(50),
@Username varchar(50),
@PasswordNew varchar(50),
@Email varchar(50)
)

AS
BEGIN TRANSACTION


UPDATE T1
SET T1.Business_Name = @Business_Name, Address_Line_1 = @Address_Line_1, Address_Line_2 = @Address_Line_2,
Address_Line_3 = @Address_Line_3, County = @County, Provence = @Provence, Telephone = @Telephone
FROM Business T1
INNER JOIN User_Acc T2 ON T1.Business_ID = T2.Business_ID
WHERE T2.Username = @Username

UPDATE
T2
SET
T2.Email = @Email, Password = @PasswordNew
FROM
User_Acc T2
INNER JOIN Business T1
ON
T2.Business_ID = T1.Business_ID
WHERE
T2.Username = @Username



COMMIT