private void buttonKHDangKy_Click(object sender, EventArgs e)
{
frmDanhSachKHDKThuePhong dktp = new frmDanhSachKHDKThuePhong();
dktp.ShowDialog();
}
private void dangKyPhongToolStripMenuItem_Click(object sender, EventArgs e)
{
frmDanhSachKHDKThuePhong ds = new frmDanhSachKHDKThuePhong();
ds.ShowDialog();
}