How to Upload a file and how to download

protected void btnSub_Click(object sender, EventArgs e)
   {
       try
       {
           string filename = FileUpload1.FileName;

           FileUpload1.PostedFile.SaveAs(Server.MapPath("~\\Uploadform\\" + filename.Trim()));

           string path = "~\\Uploadform\\" + filename.Trim();

           OleDbConnection con = new OleDbConnection(str);//str is connection string
           cmd = new OleDbCommand("Insert into adminCircular(title,type,url1) values('" + txttitle.Text + "','" + txttype.Text + "','" + path + "')", con);
           lblinfo.Text = " Uploaded Successfully ";
           cmd.CommandType = CommandType.Text;
           con.Open();
           cmd.ExecuteNonQuery();
           con.Close();
       }
       catch (Exception ex)
       {
           Response.Write(ex.ToString());
       }
   }