private void button3_Click(object sender, EventArgs e)
{
panel1.Controls.Clear();
register r = new register();
r.TopLevel = false;
panel1.Controls.Add(r);
r.Show();
}
private void button2_Click(object sender, EventArgs e)
{
Form register = new register(this);
register.TopLevel = false;
register.AutoScroll = true;
this.flowLayoutPanel1.Controls.Clear();
this.flowLayoutPanel1.Controls.Add(register);
register.Show();
}