C# form topmost in application scope only

I was creating a little "Find" dialog box for my recent treeview application. I wanted the box to be like in Visual Studio itself, in the fact that the find box is topmost for anything in Visual Studio, but not over the rest of the programs that are running.

In the C# form designer, you can set the form to have "Topmost = true", which places the form on top of every window in the entire Windows scope. Not quite what I wanted...

To get it to be topmost, you need to call the Show() method when displaying the form, passing to it a reference to the parent form that it will always be on top of. Like so:

FindForm frm = new FindForm();

frm.Show(this);

(FindForm is my search dialog, and this is the parent form calling it)

Now it's topmost in the application scope but not in the Windows scope!