Linking Listboxes

Question

Any help would be appreciated on this assignment.

The Sunshine Subdivision allows residents to select siding for their new  homes, but only specific trim colors are allowed wih each siding color.  Create a Form that allows a user to choose one of three siding colors from a ListBox white, gray, or blue. When the user selects a siding color, the program should display a second listbox that contains only the following choices:
White siding- black, red, green or dark blue trim
Gray siding- black or white trim
Blue siding- white or dark blue trim


After the user selects a trim color, the program should display a congratulatory message on a label indicating that the choice is a good one. The trim listbox also becomes invisible.  If the user makes a new selection from the siding ListBox. the congratulatory message is invisible until the user selects a complementary trim.

I have started but have not got very far, I  just have no clue as how to add the second Listbox.

Thanx
James