private void button2_Click(object sender, EventArgs e)
{
DanhSachSBD f = new DanhSachSBD();
f.Show();
}
private void đánhSốBáoDanhToolStripMenuItem1_Click(object sender, EventArgs e)
{
if (!CheckExitsFrom("DanhSachSBD"))
{
DanhSachSBD fm = new DanhSachSBD();
fm.MdiParent = this;
fm.Show();
}
else ActiveChildForm("DanhSachSBD");
}