C# Textbox focus at startup

using System;
using System.Drawing;
using System.Windows.Forms;
 
public delegate void onStartDelegate();
 
class GUI : Form
{
    public TextBox myBox = new TextBox();
    public RichTextBox myTextArea = new RichTextBox();
    public event onStartDelegate onGUIStart;
 
    public GUI()
    {
        /* Define form layout */
        this.Height = 500;
        this.Width = 600;
        this.Text = "Bills Program Alpha 1.0";
        this.MaximizeBox = false;
        this.CenterToScreen();
        this.MaximumSize = new Size(600, 500);
        this.MinimumSize = new Size(600, 500);
        this.BackColor = Color.DarkGoldenrod;
 
        /* Create textbox */
        myBox.Parent = this;
        myBox.Size = new Size(ClientSize.Width + 5, 10);
        myBox.Location = new Point(-2, (ClientSize.Height - myBox.Height));
        myBox.BackColor = Color.Black;
        myBox.ForeColor = Color.LightGreen;
        myBox.Font = new Font("Courier New", 12);
        myBox.MaxLength = 30;
        myBox.TabStop = true;
        myBox.TabIndex = 0;
        myBox.Text = "Enter commands here";
        
        /* Create text area */
        myTextArea.Parent = this;
        myTextArea.Size = new Size(ClientSize.Width + 2, (ClientSize.Height - myBox.Height) + 4);
        myTextArea.Multiline = true;
        myTextArea.BackColor = Color.Black;
        myTextArea.ForeColor = Color.LightGreen;
        myTextArea.ReadOnly = true;
        myTextArea.Font = new Font("Verdana", 15);
        myTextArea.Text = "this is some testing text";
        myTextArea.ScrollBars = RichTextBoxScrollBars.Horizontal;
        myTextArea.TabStop = false;
 
        onGUIStart += new onStartDelegate(focusText);
 
        onGUIStart();
 
    }
 
    public void focusText()
    {
        myBox.Focus();
        myBox.Select();
    }
    
    [STAThread]
    static void Main()
    {
        Application.EnableVisualStyles();
        Application.Run(new GUI());
    }