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();

}