Submenus for a Nifty popup menu

I’ve been using Nifty popup menus for a few months now, and I’ve reached the point where I want one of them to have items which open submenus when activated. I searched the Internet and found a few other people who attempted this, but no evidence that any succeeded. Has anyone here actually done it?

My own efforts have reached the point where both the parent menu and the submenu are visible. However, the parent is still responding to mouse movement and the submenu is not. How could I reverse this behavior?

My immediate issue got solved by trial and error. Disabling the parent popup with Element.disable() causes the child to respond to the mouse.

I’m still interested in hearing from others who’ve walked this road.