Roy's right. Some day someone will say "Hey, what's our most problematic machine?" and then you'll post a question on here on how to figure that out.
It is not more inconvenient for the user. Seems like they'd be using the same amount of effort to pick three things from a list box vs. three things from combo boxes. Plus you get the added benefit of having your db structured properly.
If you are still intent on keeping the list box method, check HELP or this forum. When you set it to multi-select = SIMPLE or EXTENDED, it's handled differently than a text box, combo box, or a list box that has Multi-Select = NONE. You can see why--there are multiple items selected, and you have to loop thru them and put them some where. That's what fiep's code is doing.
Want to get great answers to your Tek-Tips questions? Have a look at FAQ219-2884 or FAQ222-2244