private void tlThongke_ItemClick(object sender, TileItemEventArgs e)
{
fThongKe f = new fThongKe();
this.Hide();
f.ShowDialog();
this.Show();
}
private void hóaĐơnToolStripMenuItem_Click(object sender, EventArgs e)
{
fThongKe f = new fThongKe();
f.ShowDialog();
}