if (form2 == null || form2.IsDisposed)
{
Form2 sAllPage = new Form2();
// sAllPage.FormBorderStyle = FormBorderStyle.None;
// sAllPage.Dock = DockStyle.Fill;
sAllPage.TopLevel = false;
this.panel1.Controls.Clear();
this.panel1.Controls.Add(sAllPage);
sAllPage.Show();
sAllPage.WindowState = FormWindowState.Maximized;
}
else
{
form2.Activate();
}