private void bt101_Click(object sender, EventArgs e)
{
Button bt = (Button)sender;
if (bt.BackColor == Color.White || bt.BackColor == Color.Yellow)
{
frmDatPhong frm = new frmDatPhong();
frm.UIParent = this;
frm.maPhong = bt.Text;
frm.ShowDialog();
}
else
{
}
}