Error in asp.net c# code

I have the following code, this code was recommended to me by stackoverflow user on my previous post, its throwing some error

protected void Button2_Click(object sender, EventArgs e)
    {
        String a = DropDownList1.SelectedItem.Value;
        String b = DropDownList3.SelectedItem.Value.PadLeft(3, '0');      
        String c = TextBox2.Text.PadLeft(5,'0').ToString();
        String d = TextBox3.Text.ToString();
        String digit = a+ b  + c + d;
        string sql = "select * from testcase.main where reg_no =?";

try
        {
            using (OdbcConnection myConn = new OdbcConnection("Driver={MySQL ODBC 3.51 Driver};Server=localhost;Database=testcase;User=root;Password=root;Option=3;"), 
                OdbcCommand cmd = new OdbcCommand(sql, myConn))
            {
                    myConn.Open();
             开发者_如何学Python       //**
                    cmd.Parameters.AddWithValue("?", digit);
                    using (odbcReader MyReader = cmd.ExecuteReader())
                    {
                        //**
                        while (MyReader.Read())
                        {
                            String f = MyReader["pet_name"].ToString();
                            String g = MyReader["res_name"].ToString();

                            Label9.Visible = true;
                            Label9.Text = f;

                            Label10.Visible = true;
                            Label10.Text = "VS";

                            //Label11.Visible = true;
                            Label11.Text = g;

                        }
                    }
                }
            }

        catch (Exception e1)
        {
            Response.Write(e1.ToString());
        }
    }

the error is:

Error 1 Cannot use more than one type in a for, using, fixed, or declaration statement 

How can i resolve this error??what is the problem in declaration?

You have two variables wrapped in a using statement:

using (OdbcConnection myConn = new OdbcConnection("Driver={MySQL ODBC 3.51 Driver};Server=localhost;Database=testcase;User=root;Password=root;Option=3;"), 
                OdbcCommand cmd = new OdbcCommand(sql, myConn))

Separate them into two nested using statements.

using( IDisposable obj1 )
{
    using( IDisposable obj2 )
    {
         // code
    }
}

Have you tried it without having both myConn and cmd in this line:

        using (OdbcConnection myConn = new OdbcConnection("Driver={MySQL ODBC 3.51 Driver};Server=localhost;Database=testcase;User=root;Password=root;Option=3;"), 
            OdbcCommand cmd = new OdbcCommand(sql, myConn))

I believe you had some typos. Please try this:

protected void Button2_Click(object sender, EventArgs e)
{
    String a = DropDownList1.SelectedItem.Value;
    String b = DropDownList3.SelectedItem.Value.PadLeft(3, '0');      
    String c = TextBox2.Text.PadLeft(5,'0').ToString();
    String d = TextBox3.Text.ToString();
    String digit = a+ b  + c + d;
    string sql = "select * from testcase.main where reg_no =?";

    try
    {
        using (OdbcConnection myConn = new OdbcConnection("Driver={MySQL ODBC 3.51 Driver};Server=localhost;Database=testcase;User=root;Password=root;Option=3;"))
        using (OdbcCommand cmd = new OdbcCommand(sql, myConn))
        {
            myConn.Open();
            //**
            cmd.Parameters.AddWithValue("?", digit);
            using (OdbcDataReader MyReader = cmd.ExecuteReader())
            {
                //**
                while (MyReader.Read())
                {
                    String f = MyReader["pet_name"].ToString();
                    String g = MyReader["res_name"].ToString();

                    Label9.Visible = true;
                    Label9.Text = f;

                    Label10.Visible = true;
                    Label10.Text = "VS";

                    //Label11.Visible = true;
                    Label11.Text = g;

                }
            }
        }
    }
    catch (Exception e1)
    {
        Response.Write(e1.ToString());
    }
}

You cannot declare variables of two different types in a single using statement.

You need to declare the OleDbConnection and OleDbCommand in two different using statements:

using (OdbcConnection myConn = new OdbcConnection("Driver={MySQL ODBC 3.51 Driver};Server=localhost;Database=testcase;User=root;Password=root;Option=3;"))
using (OdbcCommand cmd = new OdbcCommand(sql, myConn)) {
    ...
}