private void checkBox1_CheckedChanged(object sender, EventArgs e)
    {
        if (checkBox1.Checked)
        {
            TickCounter.Text = "The timer has started";
            tPeriodic.Enabled = true;
        }
        else
        {
            TickCounter.Text = "The timer has ended";
            tPeriodic.Enabled = false;
        }

    }

    private void TickCounter_ValueChanged(object sender, EventArgs e)
    {
        TickCounter.Text = TickCounter.Value.ToString();
    }

    private void tPeriodic_Tick(object sender, EventArgs e)
    {
        TickCounter.Value += 1;
    }

    private void label1_Click(object sender, EventArgs e)
    {
        TickCounter.Text = TickCounter.Value.ToString();
    }

    private void Form1_Load(object sender, EventArgs e)
    {

    }
}