Silas - 2005.08.24 - Here one code I used in one of my applications: I call this hierarquical listbox, because when you select one item of the left listbox (Parent) it changes all items of the right one (Child).
bind Listbox <<ListboxSelect>> {
set index [.lstPattern curselection]
puts index
set Child [lindex $Everything $index]
}
listbox .lstPattern -listvariable Pattern
listbox .lstChild -listvariable Child
pack .lstPattern .lstChild -side left
set Pattern {one two three}
set Everything {{child2 another blabla} {child2 go blabla} {child3 {another row}}}