im trying to upload an image into sql server 2008

protected void btnadd_Click(object sender, EventArgs e)
        {
            if (FileUpload1.PostedFile != null
                && FileUpload1.PostedFile.FileName != "")
            {
                byte[] myimage = new byte[FileUpload1.PostedFile.ContentLength];
                HttpPostedFile Image = FileUpload1.PostedFile;
                Image.InputStream.Read(myimage, 0, (int)FileUpload1.PostedFile.ContentLength);
                SqlConnection myConnection = new SqlConnection("Data Source=MAC-PC\\SQLEXPRESS;Initial Catalog=Populate_Pictures;Integrated Security=True");
                SqlCommand storeimage = new SqlCommand("Insert_into_Populate_pictures"
                    + "(image_content,image_type,image_size)"
                    + "values(@image_content,@image_type,@image_size)", myConnection);
                storeimage.Parameters.Add("@image_content", SqlDbType.Image, myimage.Length).Value = myimage;
                storeimage.Parameters.Add("@imagtype", SqlDbType.VarChar, 100).Value
                    = FileUpload1.PostedFile.ContentType;
                storeimage.Parameters.Add("@imagesize", SqlDbType.BigInt, 9999).Value
                    = FileUpload1.PostedFile.ContentLength;
                myConnection.Open();
                storeimage.ExecuteNonQuery();
                myConnection.Close();
                GridView1.DataSource = FetchAllImagesInfo();
                GridView1.DataBind();
            }
        }

        public DataTable FetchAllImagesInfo()
    {
        string sql="Select * from Candidate_Images";
        SqlDataAdapter da = new SqlDataAdapter(sql, "Data Source=MAC-PC\\SQLEXPRESS;Initial Catalog=Populate_Pictures;Integrated Security=True");
        DataTable dt= new DataTable ();
       da.Fill(dt);
       return dt;
    }
    }