private void Button_Click(object sender, EventArgs e)
{
Button senderB = (Button)sender;
if (but != senderB)
{
kol = 0;
but = senderB;
}
if (senderB.Text != "" && senderB.Text != "9")
{
kol = Convert.ToInt16(senderB.Text);
}
kol++;
senderB.Text = Convert.ToString(kol);
Fill1();
sd = new Sudoku();
sd.Correct(btn, b);
if (kol == 9)
{
kol = 0;
}
}