C# windows label display with button

Good afternoon expert,

Studying C#. Looking at example 2 at
http://download.iticentral.com/DevCentral/pdf/intro_Csharp.pdf

Used this example to create console application which displays the sentence
'The apple varieties ar Macintosh, Granny, and Cortland.' Inane to be sure
but hey, you gotta start somewhere.

I hate console applications so I morphed the console app into a Windows
appl using a button and a label. I kept the public class containing an instance
variable and a contruct with the same name as the class in a separate
file and the two files which do this are callled AppleMain.cs and Apple.cs
below.

Trying to go the next step create a windows app where a button displays the varieties.
I can get it to work as a single file, Apple_Win_Btn.cs, below. Attempted to
create a separate cs file in which a public class called Apple is created and objects
are created like Apple mac = new Apple(Macintosh") and then those objects are referred to
in onClick method like label1.Text = ("The apple varietys are " + Apple.Apple.Mac.Text);
and a couple of other ways but I can't get it to work. This gives me an error
No overload for method 'Apple' takes '1' arguments   and
Apple.Apple' does not contain a definition for 'Apple'

How can I separate Apple class and refer to it in the form method?

Thanks.

Allen in Dallas

+++++++++++++AppleMain.cs+++++++++++++++
// using apple console application with Windows message box

using System;
using System.Windows.Forms;

namespace Apple
{
      class AppleMain
      {
            // main entry point for application
            static void Main( string[] args )
            {
                  //
                  // TODO: Add code to start application here
                  //

                  Apple mac = new Apple("Macintosh");
                  Apple gra = new Apple("Granny Smith");
                  Apple cor = new Apple("Cortland");
                  mac.outputVariety();
                  gra.outputVariety();
                  cor.outputVariety();

//      MessageBox.Show( "Apple varietys are " + mac.outputVariety() + "," + gra.outputVariety() + ","       + cor.outputVariety(), MessageBoxButtons.OK, MessageBoxIcon.Information );
MessageBox.Show( "The apple varietys are " + mac.outputVariety() + ", " + gra.outputVariety() + ", " + cor.outputVariety(), "Display apple varietys", MessageBoxButtons.OK, MessageBoxIcon.Information );

            } // end Main

      } // end class AppleMain

} // end namespace Apple


+++++++++++++Apple.cs+++++++++++++++
using System;

namespace Apple
{
      public class Apple
      {
            private string variety = "";
            public Apple(string appleVariety)
            {
                  this.variety = appleVariety;
            }
            public string outputVariety()
            {
            return this.variety;
                  //System.Console.WriteLine(variety);
                        
            }
      }
}


++++++++++++++++++Apple_Win_Btn.cs+++++++++++++++++
using System;
using System.Drawing;
using System.Collections;
using System.ComponentModel;
using System.Windows.Forms;
using System.Data;
namespace Apple
{
      public class Form1 : System.Windows.Forms.Form
      {
            private System.Windows.Forms.Button button1;
            public System.Windows.Forms.Label label1;
            private System.ComponentModel.Container components = null;
            public Form1()
            {
                  // Required for Windows Form Designer support
                  InitializeComponent();
            }
            /// Clean up any resources being used.
            protected override void Dispose( bool disposing )
            {
                  if( disposing )
                  {
                        if (components != null)
                        {
                              components.Dispose();
                        }
                  }
                  base.Dispose( disposing );
            }
            #region Windows Form Designer generated code
            /// Required method for Designer support - do not modify
            /// the contents of this method with the code editor.
            private void InitializeComponent()
            {
                  this.button1 = new System.Windows.Forms.Button();
                  this.label1 = new System.Windows.Forms.Label();
                  this.SuspendLayout();
                  //
                  // button1
                  //
                  this.button1.Location = new System.Drawing.Point(80, 16);
                  this.button1.Name = "button1";
                  this.button1.Size = new System.Drawing.Size(168, 23);
                  this.button1.TabIndex = 0;
                  this.button1.Text = "Display apple varieties";
                  this.button1.Click += new System.EventHandler(this.button1_Click);
                  //
                  // label1
                  //
                  this.label1.Location = new System.Drawing.Point(32, 64);
                  this.label1.Name = "label1";
                  this.label1.Size = new System.Drawing.Size(272, 24);
                  this.label1.TabIndex = 2;
                  //
                  // Form1
                  //
                  this.AutoScaleBaseSize = new System.Drawing.Size(5, 13);
                  this.ClientSize = new System.Drawing.Size(328, 110);
                  this.Controls.Add(this.label1);
                  this.Controls.Add(this.button1);
                  this.Name = "Form1";
                  this.Text = "Display apple varieties";
                  this.ResumeLayout(false);

            }
            #endregion

            /// <summary>
            /// The main entry point for the application.
            /// </summary>
            [STAThread]
            static void Main()
            {
                  Application.Run(new Form1());
            }
            public string varietiesMac;      
            public string varietiesGra;
            public string varietiesCor;
            
            private void button1_Click(object sender, System.EventArgs e)
            {
                  varietiesMac = "Macintosh";
                  varietiesGra = "Granny";
                  varietiesCor = "Cortland";
                                               //label1.Text = ("The apple varietys are Macintosh, Granny and Cortland");
            label1.Text = ("The apple varietys are " + varietiesMac + ", " +       varietiesGra + ", " + varietiesCor + ".");
            }
      }
}