private void loadTour()
{
Form f = isActive(typeof(frmTour));
if (f == null)
{
frmTour fTour = new frmTour();
fTour.MdiParent = this;
fTour.Show();
}
}
private void quảnLýTourToolStripMenuItem_Click(object sender, EventArgs e)
{
Form frmtour = new frmTour();
frmtour.ShowDialog();
}