Open file dialog with fixed dialog formborder style

I want to open file dialog in window application, but that file dialog should not be re-sizable, means that dialog can't re-size just as a fixed dialog. I have attached an image开发者_如何学Cs, want to remove re-sizable that is in red circle... I am using C#.net

I think you shouldn't do that. Simply because this is a behavior a normal windows user wouldn't expect and what would be your benefit if this would be possible (against the drawbacks the user has to take into account)?