Border flick

Hi all,
I have a VN.NET application using MDIMain and MDIClients. All of the
MDIClient, I set the FormBorderStyle = None but at the runtime, all
MDIClients were displayed its border and turned the border off in very short
time. Can someone tell me how to prevent this annoyance.

I use the functions frmMDIClient.show() and frmMDIClient.Focus() to display
the MDIClient forms.

Thanks in advance,
TH