help me in inserting data using dataset and dataadapter in 3 tier

class dbcon
    {
        public static string connectionString= "Provider=Microsoft.Jet.OLEDB.4.0;Data source=E:\\testdb.mdb";
       
        OleDbConnection MAconn;
        OleDbCommand MAcmd;
        public DataSet insertRecord(String query)
        {
            DataSet ds = null;
            try
            {
                OleDbDataAdapter dataAdapter = new OleDbDataAdapter(query, connectionString);
                OleDbCommandBuilder cmd = new OleDbCommandBuilder(dataAdapter);
                ds = new DataSet();
                dataAdapter.Fill(ds);
                
                dataAdapter.Update(ds);
                
            }
            catch (Exception ex)
            {
                // MessageBox.Show(ex.Message);
            }
            return ds;
        }

using propertieslayer;

namespace databaselayer
{
    public class adddelBookDbl
    {
        dbcon obj=new dbcon();
        public DataSet dal_insert(adddelBookProps p)
        {
            string query = "select * from books ";
            DataSet ds = obj.insertRecord(query);

            return ds;
        }

namespace businesslayer
{
    public class admenRegBll
    {
        admenRegDbl d = new admenRegDbl();
        adddelBookDbl t = new adddelBookDbl();
       
        public DataSet binsert(adddelBookProps p)
        {
           DataSet ds = t.dal_insert(p);
           return ds; 
        }

protected void btnadd_Click(object sender, EventArgs e)
    {
        adddelBookProps p = new adddelBookProps();
        admenRegBll obj = new admenRegBll();
      
        DataSet ds = obj.binsert(p);
      
        DataTable dt = ds.Tables["Table"];
        dt.TableName = "books";

        // Insert the Data
        DataRow dr = ds.Tables["books"].NewRow();
        dr["bookno"] = booknotxt.Text;
        dr["isbn"] = isbntxt.Text;
        dr["booktitle"] = booktitletxt.Text;
        dr["author"] = authortxt.Text;
        dr["quantity"] = quantitytxt.Text;
        dr["price"] = pricetxt.Text;
        dr["pubyear"] = pytxt.Text;
        ds.Tables["books"].Rows.Add(dr);
    }

namespace propertieslayer
{
    public class adddelBookProps
    {
        private string bookno;
        public string Bookno
        {
            get { return bookno; }
            set { bookno = value; }
        }
        private string isbn;

        public string Isbn
        {
            get { return isbn; }
            set { isbn = value; }
        }

        private string booktitle;

        public string Booktitle
        {
            get { return booktitle; }
            set { booktitle = value; }
        }

        private string author;

        public string Author
        {
            get { return author; }
            set { author = value; }
        }

        private string quantity;

        public string Quantity
        {
            get { return quantity; }
            set { quantity = value; }
        }

        private string price;

        public string Price
        {
            get { return price; }
            set { price = value; }
        }

        private string publishedyear;

        public string Published
        {
            get { return publishedyear; }
            set { publishedyear = value; }
        }
    }