private void mnHoSoNV_Click(object sender, System.EventArgs e)
{
frmNV f = new frmNV();
f.MdiParent = this;
f.Show();
}
private void mnHoSoNV_Click(object sender, System.EventArgs e)
{
frmNV f = new frmNV();
f.MdiParent = this;
f.Show ();
}