Any Modules to help with price caculator? Ive made a booking form using Drupal 6, where bookings are a content type and you create a node of that type to make a booking.

I now need to add a price calculator. When creating a booking node, one of the CCK fields you fill in is distance. I then need the price to be calculated from the rates below, and that value to be given to another CCK field.

Rates: 
0-5 km $20/ mile 
5-10 km $15/ mile 
10-20 km $10/ mile 
20-30 km $5/ mile

So if the distance was 11km, the price would be 11 x 15 = 165. Also, the rates table needs to be editable by the site admin.

Can any modules do or at least help with this? I could probably manage to do the calculations and change the price field value with jQuery. If the table was shown on the page then jQuery could grab the values from it, and the table could be editable by the admin so the rates could be changed. Im far from a jQuery expert though and I love Drupal's ability to do powerful stuff without writing code. 
Thanks
if you need an admin interface for this your best bet is to write a small module for it in PHP, not jQuery. Unless you want your "rates table" to be handled by nodes as well..