fileupload control with dropdownlist

public partial class Fileupload : System.Web.UI.Page
{
    SqlConnection conn = new SqlConnection(ConfigurationManager.ConnectionStrings["ConnectionString"].ConnectionString);
    SqlCommand cmd1; 
    protected void Page_Load(object sender, EventArgs e)
    {
        if (!IsPostBack)
        {
            Filldrop();
        }
    }
    private void Filldrop()
    {
        SqlConnection conn = new SqlConnection(ConfigurationManager.ConnectionStrings["ConnectionString"].ConnectionString);
        SqlCommand cmd=new SqlCommand();
        cmd.CommandType = CommandType.StoredProcedure;       
        cmd.CommandText = "Select_File8";        
        cmd.Connection = conn;
        conn.Open();
        //cmd1.Parameters.Add("@FileName ", SqlDbType.VarChar).Value = FileUpload1.FileName; 
        // SqlDataAdapter da = new SqlDataAdapter(cmd);       
        SqlDataAdapter ad = new SqlDataAdapter(cmd);
        cmd.Parameters.Clear();   
        ad.SelectCommand = cmd;
        ad.SelectCommand.Parameters.Add("@FileName", SqlDbType.VarChar).Value = FileUpload1.FileName;    
        //cmd1.Parameters.Add("@FileID", SqlDbType.VarChar).Value = 1;
        DataSet ds = new DataSet();
        ad.Fill(ds,"Files");       
        //DropDownList1.DataTextField = "FileName ";
        //DropDownList1.DataValueField = "FileName ";
        DropDownList1.DataSource = ds;
        DropDownList1.DataBind();
        conn.Close();
    }
    
    protected void Button1_Click(object sender, EventArgs e)
    {
        try
        {
            if (FileUpload1.HasFile)
            {
                int filsize = FileUpload1.PostedFile.ContentLength;
                byte[] filebyt = new byte[filsize];
                FileUpload1.PostedFile.InputStream.Read(filebyt, 0, filsize);
                SqlConnection conn = new SqlConnection(ConfigurationManager.ConnectionStrings["ConnectionString"].ConnectionString);
                cmd1 = new SqlCommand();
                cmd1.CommandType = CommandType.StoredProcedure;
                cmd1.CommandText = "File_Upload";
                cmd1.Connection = conn;
                // SqlDataAdapter da = new SqlDataAdapter(cmd);
                conn.Open();  
                cmd1.Parameters.AddWithValue("@FileName ", Path.GetFileName(FileUpload1.PostedFile.FileName));
                cmd1.Parameters.AddWithValue("@Files ", filebyt);               
                int result = cmd1.ExecuteNonQuery();
                conn.Close(); 
                cmd1.Dispose(); 
                conn.Dispose(); 
                filebyt = null;
                Response.Write("File uploaded");
            }
        }
        catch (Exception ex)
        {
            Response.Write(ex.Message);
        }
    }
    protected void Button2_Click(object sender, EventArgs e)
    {
        try
        {
            string strname = string.Empty;
            string name = DropDownList1.SelectedItem.Value;
            SqlConnection conn = new SqlConnection(ConfigurationManager.ConnectionStrings["ConnectionString"].ConnectionString);
            cmd1 = new SqlCommand();
            cmd1.CommandType = CommandType.StoredProcedure;
            cmd1.CommandText = "Select_File2";
            cmd1.Connection = conn;
            // SqlDataAdapter da = new SqlDataAdapter(cmd);
            conn.Open();   
            SqlDataReader dr = cmd1.ExecuteReader();
            while (dr.Read())
            {
                strname = dr["FileName "].ToString();
                Byte[] filbyt = (Byte[])dr["Files "];
                FileStream filstr = new FileStream(Server.MapPath("Documents")+ @"\" + strname, FileMode.OpenOrCreate);
                filstr.Write(filbyt, 0, filbyt.Length);
                filstr.Close(); 
                filstr.Dispose();
                filbyt = null;
            }
            conn.Close(); 
            cmd1.Dispose(); 
            conn.Dispose();
            if (strname != string.Empty)
            {
                Response.Redirect(@"Documents/" + strname);
            }
        }
        catch (Exception ex)
        {
            Response.Write(ex.Message);
        }
    }

    
}

ALTER PROCEDURE [dbo].[Select_File8]
AS
declare @FileName varchar(50)
BEGIN
    Select  FileName from Files
END