How would you do this?

[eluser]Rok Biderman[/eluser]
Well, I'm afraid this will state the obvious, but still. How about you make a table with 17 colums (id, name and 15 destinations), then make 15 entries to cover all options. After that you just make a query that does essentially this: select (1st input dropdown value) from yourtable where (name = 2nd input dropdown value). I suppose the tax rate doesn't change, so it's easy to get the total. If they do you figure out whether it's based on the origin or destination and make another column and then select that as well. Hope it helps. Yell if you need more guidance on how to do it.