c# aplication for login page with picture upload in registration page..thr is an error..plz help

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;
using System.IO;

namespace assign
{
    public partial class Registerpage : Form
    {
        public Registerpage()
        {
            InitializeComponent();
        }

        private void button2_Click(object sender, EventArgs e)
        {
            if (textBox1.Text != "" && textBox2.Text != "" && textBox3.Text != "")
            {

                string empid = textBox1.Text;
                string emppass = textBox2.Text;
                string empname = textBox3.Text;
                string empadd = richTextBox1.Text;
                string empimg = label5.Text;
                SqlConnection con = new SqlConnection(@"Data Source=.\sqlexpress;Initial Catalog=emp;Integrated Security=True");
                MemoryStream ms = new MemoryStream();
                pictureBox1.Image.Save(ms, System.Drawing.Imaging.ImageFormat.Jpeg);
                byte[] pic_arr = new byte[ms.Length];
                ms.Position = 0;
                ms.Read(pic_arr, 0, pic_arr.Length);

                SqlCommand cmd = new SqlCommand("insert into emp1(empid,emppass,empname,empadd,empimg) values(@empid,@emppass,@empname,@empadd,@empimg)",con);
                cmd.Parameters.AddWithValue("@empid",textBox1.Text);
                cmd.Parameters.AddWithValue("@emppass", textBox2.Text);
                cmd.Parameters.AddWithValue("@empname", textBox3.Text);
                cmd.Parameters.AddWithValue("@empadd", richTextBox1.Text);
                cmd.Parameters.AddWithValue("@empimg", pic_arr);


                con.Open();
                try
                {
                    int i = cmd.ExecuteNonQuery();
                    if (i < 0)
                    {
                        MessageBox.Show("Registration Completed...!");
                        textBox1.Text = "";
                        textBox2.Text = "";
                        textBox3.Text = "";
                        richTextBox1.Text = "";
                        label5.Text = "";

                    }
                }

                catch (Exception ex)
                {
                    MessageBox.Show(ex.Message);
                }
                finally
                {
                    con.Close();
                }
            }
            else
            {
                MessageBox.Show("Fill up the registration filleds");
            }





        }

        private void button1_Click(object sender, EventArgs e)
        {
            openFileDialog1.ShowDialog();
            label5.Text = openFileDialog1.FileName;
            //For diplaying image.
            string empimg = label5.Text;
            FileInfo fobj = new FileInfo(empimg);
            if (fobj.Exists)
            {
                pictureBox1.Image = Image.FromFile(empimg);
            }
            else
            {
                MessageBox.Show("Not Uploaded");
            }
        }
    }
}