Kleine Frage f�r C#.

Ich lerne seit paar Tagen C#.
(Danach m�chte ich mir noch C++ aneignen, aber daran denke ich im Moment nicht.)

Jetzt die Frage: Ich habe folgendes geschrieben:

Spoiler

Code:

public partial class Form1 : Form
        {
            Label firstclicked = null;
            Label secondclicked = null;
        }

Form1 wird aber als Fehler angezeigt.. Was ist daran falsch?

Kompletter Code zur �bersicht:

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;

namespace WindowsFormsApplication1
{
    public partial class Form1 : Form
    {
        Random random = new Random();

        List<string> icons = new List<string>()
        {
            "!", "!", "a", "a", "q", "q", "?", "?",
            "x", "x", "b", "b"
        };

        private void AssignIconsToSquares()
        {
            foreach (Control control in tableLayoutPanel1.Controls)
            {
                Label iconlabel = control as Label;
                if (iconlabel != null)
                {
                    int randomNumber = random.Next(icons.Count);
                    iconlabel.Text = icons[randomNumber];
                    iconlabel.ForeColor = iconlabel.BackColor;
                    icons.RemoveAt(randomNumber);
                }
            }
        }
        
        public Form1()
        {
            InitializeComponent();

            AssignIconsToSquares();
        }

        private void label_Click(object sender, EventArgs e)
        {
            Label clickedlabel = sender as Label;

            if (clickedlabel != null)
            {
                if (clickedlabel.ForeColor == Color.Black)
                    return;

                if (clickedlabel == null)
                {
                    if (clickedlabel.ForeColor == Color.Black)
                        return;

                    if (firstclicked == null)
                    {
                        firstclicked = clickedlabel;
                        firstclicked.ForeColor = Color.Black;

                        return;
                    }

                }
            }
        }

        public partial class Form1 : Form
        {
            Label firstclicked = null;
            Label secondclicked = null;
        }

        private void timer1_tick( object sender, EventArgs e)
        {
            timer1.Stop();

            firstclicked.ForeColor = firstclicked.BackColor;
            secondclicked.ForColor = secondclicked.BackColor;

            firstclicked = null;
            secondclicked = null;
        }

        private void label_Click(object sender, EventArgs e)
        {
            if (timer1.Enabled == true)
                return;
            
            Label clickedLabel = sender as Label;
            
            if (clickedLabel != null)
            {
                if (clickedLabel.ForeColor == Color.Black)
                    return;
                
                if (firstClicked == null)
                {
                    firstClicked = clickedLabel;
                    firstClicked.ForeColor = Color.Black;
                    return;
                }
                
                secondClicked = clickedLabel;
                secondClicked.ForeColor = Color.Black;
                
                timer1.Start();
            }
        }
    }
}

Kann mir eventuell jemand helfen?