private void Show()
        {
            DataTable      dt      = new DataTable();
            SqlDataAdapter adapter = new SqlDataAdapter("SELECT * FROM book_master_tbl", Con1.Connect());

            adapter.Fill(dt);
            GridView1.AutoGenerateColumns = false;
            GridView1.DataSource          = dt;
            GridView1.DataBind();



            adapter = new SqlDataAdapter("SELECT author_name FROM author_master_tbl;", Con1.Connect());
            dt      = new DataTable();
            adapter.Fill(dt);
            DropDownList_AuthorName.DataSource     = dt;
            DropDownList_AuthorName.DataValueField = "author_name";
            DropDownList_AuthorName.DataBind();

            adapter = new SqlDataAdapter("SELECT publisher_name FROM publisher_master_tbl;", Con1.Connect());
            dt      = new DataTable();
            adapter.Fill(dt);
            DropDownList_Publisher.DataSource     = dt;
            DropDownList_Publisher.DataValueField = "publisher_name";
            DropDownList_Publisher.DataBind();
        }
        void FillAuthorPublisherValues()
        {
            try {
                SqlConnection con = new SqlConnection(strcon);
                if (con.State == ConnectionState.Closed)
                {
                    con.Open();
                }
                SqlCommand     cmd         = new SqlCommand("Select author_name from dbo.author_master_tbl;", con);
                SqlDataAdapter dataAdapter = new SqlDataAdapter(cmd);
                DataTable      dataTable   = new DataTable();
                dataAdapter.Fill(dataTable);
                DropDownList_AuthorName.DataSource     = dataTable;
                DropDownList_AuthorName.DataValueField = "author_name";
                DropDownList_AuthorName.DataBind();

                cmd         = new SqlCommand("Select publisher_name from dbo.publisher_master_tbl;", con);
                dataAdapter = new SqlDataAdapter(cmd);
                dataTable   = new DataTable();
                dataAdapter.Fill(dataTable);
                DropDownList_Publisher.DataSource     = dataTable;
                DropDownList_Publisher.DataValueField = "publisher_name";
                DropDownList_Publisher.DataBind();
            } catch (Exception ex) {
            }
        }