I am making a calculation, but then I came up with the idea to automatically make that calculation as I fill in `textBox1`. How I can call that calculation that is inside `button1_Click`? I know how to copy to `textBox2` what you wrote in `textBox1`, but my knowledge is to little for to call a whole if statement calculation to auto update `Total` inside `textBox2` when I was writing numbers inside `textBox1` without a button. 

```
private void textBox1_TextChanged(object sender, EventArgs e) { }
private void textBox2_TextChanged(object sender, EventArgs e) { }
private void button1_Click(object sender, EventArgs e)
{
    aantalgroep = int.Parse(textBox1.Text);

    /* Wat er gebeurd bij RadioButton1 Checked */
    if (radioButton1.Checked) 
    {
        number = aantalgroep * 8;
        textBox2.Text = number.ToString();

        if (aantalgroep < 10)
            textBox2.Text = number.ToString();
    }
}

```