private void btnPT_Click(object sender, EventArgs e)
{
frmPhieuThuePhong PT = new frmPhieuThuePhong();
PT.ShowDialog();
}
private void LapPhieuThuePhongToolStripMenuItem_Click(object sender, EventArgs e)
{
frmPhieuThuePhong Child = new frmPhieuThuePhong();
Child.MdiParent = this;
Child.Show();
}
