private void Page_Load(object sender, System.EventArgs e)
        {
            if(Session["ItemID"]!=null)
            {
                ItemId = Convert.ToInt32(Session["ItemID"]);
                BindPointTable();
            } 
        }

        private void BindPointTable() 
        {
            Points.Controls.Clear();
            SqlCommand comm = new SqlCommand("SELECT point_ID,x,y FROM Points WHERE const_ID=@id ORDER BY point_ID");
            comm.Parameters.Add("@id",SqlDbType.Int, 4 );
            comm.Parameters["@id"].Value = ItemId;
            comm.Connection = conn;
            conn.Open();
            SqlDataReader dr = comm.ExecuteReader();
            while(dr.Read()) 
            {
                TableRow tr = new TableRow();
                TableCell td = new TableCell();
                td.Text = dr.GetInt32( 0 ).ToString();
                tr.Controls.Add(td);
                td = new TableCell();
                
                td.Text = "(<b>"+dr.GetDouble( 1 ).ToString()+"</b> , <b>"+dr.GetDouble( 2 ).ToString()+"</b>)";
                tr.Controls.Add(td);

                td = new TableCell();

                LinkButton lb = new LinkButton();
                lb.Text = "[x]";
                lb.CommandArgument=dr.GetInt32( 0 ).ToString();
                lb.Command += new CommandEventHandler(DeletePointButton_Click);
                td.Controls.Add(lb);
        
                tr.Controls.Add(td);

                Points.Controls.Add(tr);
            }
            conn.Close();
        }

        private void DeletePointButton_Click(object source, System.Web.UI.WebControls.CommandEventArgs e)
        {
            SqlCommand comm = new SqlCommand("DELETE FROM Points WHERE point_ID=@pid AND const_ID=@cid",conn);
            comm.Parameters.Add("@pid",SqlDbType.Int, 4 );
            comm.Parameters.Add("@cid",SqlDbType.Int, 4 );
            comm.Parameters["@pid"].Value = Convert.ToInt32(e.CommandArgument);
            comm.Parameters["@cid"].Value = ItemId;

            conn.Open();
            int items = comm.ExecuteNonQuery();
            conn.Close();
            if(items> 0 ) 
            {
                Message.Text = "Точка удалена";
            } 
            else 
            {
                Message.Text = "Невозможно удалить точку";
            }
            BindPointTable();
        }