private void chiaPhòngThiToolStripMenuItem_Click(object sender, EventArgs e)
{
if (!CheckExitsFrom("Chiaphongthi"))
{
Chiaphongthi fm = new Chiaphongthi();
fm.MdiParent = this;
fm.Show();
}
else ActiveChildForm("Chiaphongthi");
}
private void button10_Click_1(object sender, EventArgs e)
{
Chiaphongthi f = new Chiaphongthi();
f.Show();
}