Editing main dialog

[stodge]

When I create a Qt dialog, I get a main window, with the usual menu,
toolbar and status bar etc.. But how do I graphically edit this dialog?
I cant work out how to do that. I can only edit new dialogs. It seems
pointless creating a main dialog that is loaded automatically that I
can't edit.

I think this is the same with a KDE applicaiton created using the Kdevelop
"wizard"

Any help gratefully appreciated