private void toolStripMenuToLamViec_Click(object sender, EventArgs e)
{
if (f_ToLamViec == null || f_ToLamViec.IsDisposed)
{
f_ToLamViec = new frmToLamViec();
f_ToLamViec.MdiParent = this;
f_ToLamViec.Show();
}
else
f_ToLamViec.Activate();
}
private void btnTo_Click(object sender, EventArgs e)
{
frmToLamViec f_ToLamViec = new frmToLamViec();
f_ToLamViec.ShowDialog();
}