{"Operation is not valid due to the current state of the obj

Question

using System;

using System.Collections.Generic;

using System.Linq;

using System.Windows.Forms;

namespace bankloan

{

    static class Program

    {

        /// <summary>

        /// The main entry point for the application.

        /// </summary>

        [STAThread]

        static void Main()

        {

            Application.EnableVisualStyles();

            Application.SetCompatibleTextRenderingDefault(false);

            Application.Run(new Form1());

        }

    }

}

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 Oracle.DataAccess.Client;

using Oracle.DataAccess.Types;

namespace bankloan

{

    public partial class Form1 : Form

    {

        public Form1()

        {

            InitializeComponent();

        }

        private void button1_Click(object sender, EventArgs e)

        {

            string oradb = "Data Source=ORCL;User Id=scott;Password=tiger;";

            OracleConnection conn = new OracleConnection(oradb);

            conn.Open();

            OracleCommand cmd = new OracleCommand();

            cmd.Connection = conn;

            cmd.CommandText = "select count(*) from result";

            cmd.CommandType = CommandType.Text;

            OracleDataReader dr = cmd.ExecuteReader();

            dr.Read();

            int abc = int.Parse(string.Format("{0}", dr.GetValue(0)));

            MessageBox.Show(String.Empty + abc);

            cmd.CommandText = "insert into result values('no','yes','55')";

            cmd.ExecuteNonQuery();

            conn.Dispose();

            MessageBox.Show("table truncated");

        }

    }

}

getting error 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 Oracle.DataAccess.Client;

using Oracle.DataAccess.Types;

namespace bankloan

{

    public partial class Form1 : Form

    {

        public Form1()

        {

            InitializeComponent();

        }

        private void button1_Click(object sender, EventArgs e)

        {

            string oradb = "Data Source=ORCL;User Id=scott;Password=tiger;";

            OracleConnection conn = new OracleConnection(oradb);

            conn.Open();

            OracleCommand cmd = new OracleCommand();

            cmd.Connection = conn;

            cmd.CommandText = "select count(*) from result";

            cmd.CommandType = CommandType.Text;

            OracleDataReader dr = cmd.ExecuteReader();

            dr.Read();

            int abc = int.Parse(string.Format("{0}", dr.GetValue(0)));

            MessageBox.Show(String.Empty + abc);

            cmd.CommandText = "insert into result values('no','yes','55')";

            cmd.ExecuteNonQuery();

            conn.Dispose();

            MessageBox.Show("table truncated");

        }

    }

}

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 Oracle.DataAccess.Client;

using Oracle.DataAccess.Types;

namespace bankloan

{

    public partial class Form1 : Form

    {

        public Form1()

        {

            InitializeComponent();

        }

        private void button1_Click(object sender, EventArgs e)

        {

            string oradb = "Data Source=ORCL;User Id=scott;Password=tiger;";

            OracleConnection conn = new OracleConnection(oradb);

            conn.Open();

            OracleCommand cmd = new OracleCommand();

            cmd.Connection = conn;

            cmd.CommandText = "select count(*) from result";

            cmd.CommandType = CommandType.Text;

            OracleDataReader dr = cmd.ExecuteReader();

            dr.Read();

            int abc = int.Parse(string.Format("{0}", dr.GetValue(0)));

            MessageBox.Show(String.Empty + abc);

            cmd.CommandText = "insert into result values('no','yes','55')";

            cmd.ExecuteNonQuery();

            conn.Dispose();

            MessageBox.Show("table truncated");

        }

    }

}

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 Oracle.DataAccess.Client;

using Oracle.DataAccess.Types;

namespace bankloan

{

    public partial class Form1 : Form

    {

        public Form1()

        {

            InitializeComponent();

        }

        private void button1_Click(object sender, EventArgs e)

        {

            string oradb = "Data Source=ORCL;User Id=scott;Password=tiger;";

            OracleConnection conn = new OracleConnection(oradb);

            conn.Open();

            OracleCommand cmd = new OracleCommand();

            cmd.Connection = conn;

            cmd.CommandText = "select count(*) from result";

            cmd.CommandType = CommandType.Text;

            OracleDataReader dr = cmd.ExecuteReader();

            dr.Read();

            int abc = int.Parse(string.Format("{0}", dr.GetValue(0)));

            MessageBox.Show(String.Empty + abc);

            cmd.CommandText = "insert into result values('no','yes','55')";

            cmd.ExecuteNonQuery();

            conn.Dispose();

            MessageBox.Show("table truncated");

        }

    }

}

getting error {"Operation is not valid due to the current state of the object."}

at line    Application.Run(new Form1());