variable for an open window

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;

namespace FormControlAccess
  {
    //--------------------------------------------------------------------------------------------------
    // 3 things are needed to access the controls on another form without specifically declaring vars to do so
    // 1. Need to know the form Name
    // 2. Need to know the control Name
    // 3. What to send to the control
    //    1. Text
    //    2. An object of any declared type eg, Items for a combo box, List Box
    //--------------------------------------------------------------------------------------------------
   

    public partial class frmMain : Form
      {
      internal frmChild form1;
      internal frmChild1 form2;
      internal frmChild[] newForms = new frmChild[0];
 
      public frmMain()
        {
            InitializeComponent();
            form1 = new frmChild();
            form2 = new frmChild1();
            lbForms.Items.Add("...");
        }
      //--------------------------------------------------------------------------------------------------
      private void Form1_Load(object sender, EventArgs e)
        {
        form1.Show();
        form2.Show();
        this.Top = 10;
        this.Left = (Screen.PrimaryScreen.Bounds.Width - this.Width) / 2;
        form1.Top = (this.Top + this.Height) + 10;
        form2.Left = form1.Left + form1.Width;
        form2.Top = form1.Top;
        form1.BringToFront();
        //Set the form that will receive the control values
        agent.SendToForm = form1;
        lbForms.Items.AddRange(agent.GetFormNames());
        }
      //--------------------------------------------------------------------------------------------------
      private void button1_Click(object sender, EventArgs e)
        {
        agent.Ctrl(agent.SendToForm, "textBox1").Text = te.Text;
        }
      //--------------------------------------------------------------------------------------------------
      private void button3_Click(object sender, EventArgs e)
        {
        agent.Ctrl(agent.SendToForm, "textBox2").Text = te.Text;
        }
      //--------------------------------------------------------------------------------------------------
      private void button2_Click(object sender, EventArgs e)
        {
        //send to Text property of the Combio Box
        agent.Ctrl(agent.SendToForm, "comboBox1").Text = te.Text;
       
        //Add Item to Combo Box
        ((ComboBox)agent.Ctrl(agent.SendToForm, "comboBox1")).Items.Add(te.Text);
       
        //Declare local Combo Box pointing to Combo Box on child form
        ComboBox c = ((ComboBox)agent.Ctrl(agent.SendToForm, "comboBox1"));

        //Add items to combo box via it's surrogate c
        c.Items.Add(te.Text);
       
        //Set the selected index to the item just added
        c.SelectedIndex = c.Items.Count - 1;
        }
      //--------------------------------------------------------------------------------------------------
      private void button4_Click(object sender, EventArgs e)
        {
        //Add Item to Combo Box
        ((ListBox)agent.Ctrl(agent.SendToForm, "listBox1")).Items.Add(te.Text);

        //Declare local Combo Box pointing to Combo Box on child form
        ListBox lb = ((ListBox)agent.Ctrl(agent.SendToForm, "listBox1"));

        //Add items to combo box via it's surrogate c
        lb.Items.Add(te.Text + " ...");

        //Set the selected index to the item just added
        lb.SelectedIndex = lb.Items.Count - 1;
        }
      //--------------------------------------------------------------------------------------------------
      private void button5_Click(object sender, EventArgs e)
        {
        //one way
        DataGridView dgv = ((DataGridView)agent.Ctrl(agent.SendToForm, "dg"));
        dgv.Rows[0].Cells[0].Value = te.Text;

        //((DataGridView)agent.Ctrl(agent.SendToForm, "dg")).Rows[0].Cells[0].Value = te.Text;
       
        //another way
        ((DataGridView)agent.Ctrl(agent.SendToForm, "dg")).Rows[0].Cells[1].Value = te.Text;
        }
      //--------------------------------------------------------------------------------------------------
      private void button6_Click(object sender, EventArgs e)
        {
        //one way
        ListView lv = ((ListView)agent.Ctrl(agent.SendToForm, "listView1"));
        lv.Items.Add(te.Text + " Agent 1", 0);

        //another way
        ((ListView)agent.Ctrl(agent.SendToForm, "listView1")).Items.Add(te.Text + " Agent 2", 1);
        }
      //--------------------------------------------------------------------------------------------------
      private void rb1_CheckedChanged(object sender, EventArgs e)
        {
        agent.SendToForm = form1;
        }
      //--------------------------------------------------------------------------------------------------
      private void rb2_CheckedChanged(object sender, EventArgs e)
        {
        agent.SendToForm = form2;
        }
      //--------------------------------------------------------------------------------------------------
      private void button7_Click(object sender, EventArgs e)
        {
        TreeNode root = new TreeNode();
        TreeNode n = new TreeNode();

        TreeView tv = ((TreeView)agent.Ctrl(agent.SendToForm, "tv"));
        n.Text = te.Text;
        root = tv.Nodes[0];
        tv.SelectedNode = root;
        root.Nodes.Add(n);
        root.ExpandAll();
        }
      //--------------------------------------------------------------------------------------------------
      private void bnNew_Click(object sender, EventArgs e)
        {
        Array.Resize(ref newForms, newForms.Length + 1);
        newForms[newForms.Length - 1] = new frmChild();
        newForms[newForms.Length - 1].Name = teFormName.Text + "_" + (newForms.Length - 1).ToString();
        newForms[newForms.Length - 1].Text = newForms[newForms.Length - 1].Name;
        newForms[newForms.Length - 1].Show();
        newForms[newForms.Length - 1].BringToFront();
        agent.RefreshFormList();
        lbForms.Items.Clear();
        lbForms.Items.Add("...");
        lbForms.Items.AddRange(agent.GetFormNames());

        }
      //--------------------------------------------------------------------------------------------------
      private void teFormName_TextChanged(object sender, EventArgs e)
        {
        bnNew.Enabled = (teFormName.Text.Length > 0) ? true : false;
        }
      //--------------------------------------------------------------------------------------------------
      private void lbForms_SelectedIndexChanged(object sender, EventArgs e)
        {
        if (lbForms.SelectedIndex < 4)
          return;

        agent.SendToForm = newForms[lbForms.SelectedIndex - 4];
        }
      //--------------------------------------------------------------------------------------------------


    }
}