private void Form1_Load(object sender, EventArgs e)
{
panel1.Controls.Clear();
frmGiris f3 = new frmGiris(banka);
f3.TopLevel = false;
panel1.Controls.Add(f3);
f3.Show();
f3.Dock = DockStyle.Fill;
}
private void sbtnGeri5_Click(object sender, EventArgs e)
{
Form1 f1 = Application.OpenForms["Form1"] as Form1;
Panel panel1 = f1.Controls["panel1"] as Panel;
panel1.Controls.Clear();
frmGiris f3 = new frmGiris(banka);
f3.TopLevel = false;
panel1.Controls.Add(f3);
f3.Show();
f3.Dock = DockStyle.Fill;
}