GUI Windows Form C#

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;
enum TextFontSize {
    FontSizeHuge = 30,
    FontSizeNormal = 20,
    FontSizeTiny = 8
}
public class MainWindow : Form {
    private TextFontSize currFontSize = TextFontSize.FontSizeNormal;
    private ToolStripMenuItem currentCheckedItem;
    public MainWindow() {
        InitializeComponent();
        currentCheckedItem = normalToolStripMenuItem;
        currentCheckedItem.Checked = true;
        this.toolStripTextBoxColor.LostFocus += new EventHandler(toolStripTextBoxColor_LostFocus);
    }
    private void exitToolStripMenuItem_Click(object sender, EventArgs e) {
        Application.Exit();
    }
    void toolStripTextBoxColor_LostFocus(object sender, EventArgs e) {
        BackColor = Color.FromName(toolStripTextBoxColor.Text);
    }
    private void ContextMenuItemSelection_Clicked(object sender, EventArgs e) {
        currentCheckedItem.Checked = false;
        ToolStripMenuItem miClicked = miClicked = (ToolStripMenuItem)sender;
        if (miClicked.Name == "hugeToolStripMenuItem") {
            currFontSize = TextFontSize.FontSizeHuge;
            currentCheckedItem = hugeToolStripMenuItem;
        }
        if (miClicked.Name == "normalToolStripMenuItem") {
            currFontSize = TextFontSize.FontSizeNormal;
            currentCheckedItem = normalToolStripMenuItem;
        }
        if (miClicked.Name == "tinyToolStripMenuItem") {
            currFontSize = TextFontSize.FontSizeTiny;
            currentCheckedItem = tinyToolStripMenuItem;
        }
        currentCheckedItem.Checked = true;
        Invalidate();
    }
    private void MainWindow_Paint(object sender, PaintEventArgs e) {
        Graphics g = e.Graphics;
        g.DrawString("Right click on me...", new Font("Times New Roman", (float)currFontSize), new SolidBrush(Color.Black), 50, 50);
    }
    private void InitializeComponent() {
        this.mainMenuStrip = new System.Windows.Forms.MenuStrip();
        this.fileToolStripMenuItem = new System.Windows.Forms.ToolStripMenuItem();
        this.exitToolStripMenuItem = new System.Windows.Forms.ToolStripMenuItem();
        this.changeBackgroundColorToolStripMenuItem = new System.Windows.Forms.ToolStripMenuItem();
        this.toolStripTextBoxColor = new System.Windows.Forms.ToolStripTextBox();
        this.hugeToolStripMenuItem = new System.Windows.Forms.ToolStripMenuItem();
        this.normalToolStripMenuItem = new System.Windows.Forms.ToolStripMenuItem();
        this.tinyToolStripMenuItem = new System.Windows.Forms.ToolStripMenuItem();
        this.mainMenuStrip.SuspendLayout();
        this.fontSizeContextStrip.SuspendLayout();
        this.SuspendLayout();
        // 
        this.mainMenuStrip.Items.AddRange(new System.Windows.Forms.ToolStripItem[] {
            this.fileToolStripMenuItem,
            this.changeBackgroundColorToolStripMenuItem});
        this.mainMenuStrip.Location = new System.Drawing.Point(0, 0);
        this.mainMenuStrip.Name = "mainMenuStrip";
        this.mainMenuStrip.Size = new System.Drawing.Size(300, 24);
        this.mainMenuStrip.TabIndex = 0;
        this.mainMenuStrip.Text = "menuStrip1";
        this.fileToolStripMenuItem.DropDownItems.AddRange(new System.Windows.Forms.ToolStripItem[] {
            this.exitToolStripMenuItem});
        this.fileToolStripMenuItem.Text = "&File";
        this.exitToolStripMenuItem.Text = "E&xit";
        this.exitToolStripMenuItem.Click += new System.EventHandler(this.exitToolStripMenuItem_Click);
        // 
        // changeBackgroundColorToolStripMenuItem
        // 
        this.changeBackgroundColorToolStripMenuItem.DropDownItems.AddRange(new System.Windows.Forms.ToolStripItem[] {
            this.toolStripTextBoxColor});
        this.changeBackgroundColorToolStripMenuItem.Name = "changeBackgroundColorToolStripMenuItem";
        this.changeBackgroundColorToolStripMenuItem.Text = "Change Background Color";
        // 
        // toolStripTextBoxColor
        // 
        this.toolStripTextBoxColor.DisplayStyle = System.Windows.Forms.ToolStripItemDisplayStyle.ImageAndText;
        this.toolStripTextBoxColor.Name = "toolStripTextBoxColor";
        this.toolStripTextBoxColor.Size = new System.Drawing.Size(100, 21);
        this.fontSizeContextStrip.Enabled = true;
        this.fontSizeContextStrip.GripMargin = new System.Windows.Forms.Padding(2);
        this.fontSizeContextStrip.Items.AddRange(new System.Windows.Forms.ToolStripItem[] {
            this.hugeToolStripMenuItem,
            this.normalToolStripMenuItem,
            this.tinyToolStripMenuItem});
        this.fontSizeContextStrip.Location = new System.Drawing.Point(25, 90);
        this.fontSizeContextStrip.Name = "contextMenuStrip1";
        this.fontSizeContextStrip.RightToLeft = System.Windows.Forms.RightToLeft.No;
        this.fontSizeContextStrip.Size = new System.Drawing.Size(97, 70);
        this.hugeToolStripMenuItem.Text = "Huge";
        this.hugeToolStripMenuItem.Click += new System.EventHandler(this.ContextMenuItemSelection_Clicked);
        this.normalToolStripMenuItem.Text = "Normal";
        this.normalToolStripMenuItem.Click += new System.EventHandler(this.ContextMenuItemSelection_Clicked);
        this.tinyToolStripMenuItem.Text = "Tiny";
        this.tinyToolStripMenuItem.Click += new System.EventHandler(this.ContextMenuItemSelection_Clicked);
        this.AutoScaleDimensions = new System.Drawing.SizeF(6F, 13F);
        this.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font;
        this.ClientSize = new System.Drawing.Size(300, 145);
        this.ContextMenuStrip = this.fontSizeContextStrip;
        this.Controls.Add(this.mainMenuStrip);
        this.Paint += new System.Windows.Forms.PaintEventHandler(this.MainWindow_Paint);
        this.mainMenuStrip.ResumeLayout(false);
        this.fontSizeContextStrip.ResumeLayout(false);
        this.ResumeLayout(false);
        this.PerformLayout();
    }
    private System.Windows.Forms.MenuStrip mainMenuStrip;
    private System.Windows.Forms.ToolStripMenuItem fileToolStripMenuItem;
    private System.Windows.Forms.ToolStripMenuItem exitToolStripMenuItem;
    private System.Windows.Forms.ToolStripMenuItem changeBackgroundColorToolStripMenuItem;
    private System.Windows.Forms.ToolStripTextBox toolStripTextBoxColor;
    private System.Windows.Forms.ContextMenuStrip fontSizeContextStrip;
    private System.Windows.Forms.ToolStripMenuItem hugeToolStripMenuItem;
    private System.Windows.Forms.ToolStripMenuItem normalToolStripMenuItem;
    private System.Windows.Forms.ToolStripMenuItem tinyToolStripMenuItem;
    [STAThread]
    static void Main() {
        Application.EnableVisualStyles();
        Application.Run(new MainWindow());
    }
}