[UPHPU] modal popup form over form

[MilesTogoe]

I have the case on a select box needing to have an add capability (popup 
a form to add a new element to the list table and refresh the list) 
without disturbing the filled in data on the underlaying form.   I've 
seen this done in Rails but searched around this AM trying to find a 
cool JQuery lightbox kind of dialog and didn't see anything like this - 
does anyone know of a link to a good example or tutorial of this ?