TreeView to select DataGridView Data

I'm attempting to control a datagridview filter via a treeview. I'm having difficulty getting it to function successfully. It says I have a missing operand, and when I edit the name of the column, it says it does not exist, even though it does. The datagridview is "dropped and dragged" from the database explorer.

Here is my code :

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using System.Data.SqlServerCe;

namespace Lewis_Warby_Airbrushing
{
    public partial class orderForm : Form
    {
        private DataTable orderTBL = new DataTable();

        SqlCeConnection conn = new SqlCeConnection(@"Data Source=|DataDirectory|\LWADataBase.sdf");


        public orderForm()
        {
            InitializeComponent();
        }




        neworderForm neworderForm = new neworderForm();
        private void addBTN_Click(object sender, EventArgs e)
        {
            
            if (neworderForm == null || neworderForm.IsDisposed == true)
                neworderForm = new neworderForm();
            neworderForm.ShowDialog();
           this.orderTBLTableAdapter.Fill(this.lWADataBaseDataSet.orderTBL);
        
        }

       
        public void ordersForm_Load(object sender, EventArgs e)
        {

            

            // TODO: This line of code loads data into the 'lWADataBaseDataSet.orderTBL' table. You can move, or remove it, as needed.
          this.orderTBLTableAdapter.Fill(this.lWADataBaseDataSet.orderTBL);
        
          
          string sOrder = null;
          int I = 0;
          for (I = 0; (I <= (orderTBL.Rows.Count - 1)); I++)
          {


              sOrder = orderTBL.Rows[1][1].ToString();
              treeView1.Nodes[0].Nodes.Add( sOrder);
          }
       
        
        }

        
        private void treeView1_AfterSelect(object sender, TreeViewEventArgs e)
        {
            if ((treeView1.SelectedNode == null))
            {
                orderTBLDataGridView.DataSource = null;
                return;
            }
            if ((treeView1.SelectedNode.Name == "root"))
            {
                orderTBLDataGridView.DataSource = null;
                return;
            }
            string sOrder;
            sOrder = treeView1.SelectedNode.Name;
            DataView dv = new DataView(orderTBL);
            dv.RowFilter = "Order Number"+ sOrder;
            orderTBLDataGridView.DataSource = dv;
        }

        private void orderForm_Shown(object sender, EventArgs e)
        {
            try
            {
                conn.Open();
            }

            catch (SqlCeException ex)
            {
                MessageBox.Show(ex.Message);
                return;
            }
            treeView1.Nodes.Clear();
            SqlCeCommand cmd = new SqlCeCommand("SELECT * FROM orderTBL ORDER BY[Order Number] ASC", conn);

            try
            {

                SqlCeDataReader dr = cmd.ExecuteReader();

                while (dr.Read())
                {
                    TreeNode node = new TreeNode(dr["Order Number"].ToString());
                    treeView1.Nodes.Add(node);

                }
            }

            catch (SqlCeException ex)
            {
                MessageBox.Show(ex.Message);
                return;

            }
            conn.Close();
        
        
        }
     
        
        
        

        


    }



} 

I'm using SqlCe 3.5 and C#. Here is the design of the form.