Update Licence Calculator page (JavaScript)

We're looking for someone with expertise in JavaScript and HTML to do the updating work on our Licence Calculator page. For the right person, it should be no more than 3 hours' work (based on last time).
The work will involve an overhaul and updating of the Licence Calculator code, with three particular changes we want to make to the JavaScript. We're looking for the project completed by Tuesday 3rd or Wednesday 4th February. If you're interested, why not take a look at the source code attached? (Note that the page has three identical sets of inputs, permitting customers to order several *different* items simultaneously.) And if this is the kind of language you speak fluently, please respond at your earliest convenience.
The specifics of the work are:

1. General updating of HTML code: make neater and with proper commenting so that anyone making changes in future can easily see what everything does. Should still be able to be opened by FrontPage.
2. Change coding to enable us to specify the \"Upgrade\" pricing independently of the \"New\" pricing, using a second array \"upgrades\" (we've entered it, but not hooked it up to the arithmetic); currently the upgrade pricing is hard-wired in at 35%, with an algorithm for subtracting out the media price first before multiplying by 35% and then adding the media price back in. The Upgrade pricing will in future operate parallel to the New pricing, called from its array when the customer selects \"Upgrade\" using radio button \"Upg\".
3. Change coding so we can sell systems \"licence-only\"; licence-only prices are to be calculated by subtracting the media price from the boxed-system price. Whether it's a Fixed or Floating licence (input \"Type\"), and whether Commercial/Educational/Student pricing (input \"Cust\"), and whether New system or Upgrade (input \"Upg\"), the licence-only price should be £30/£20/£15 less for Scientific WorkPlace/Scientific Word/Scientific Notebook respectively (input \"Product\"); see the array \"media\". We've arranged the HTML layout to show this, but - again - not hooked up the calculation side. The Carriage tally (input T4) should reflect the number of *boxed* systems, as at present.
4. The Dictionary option (input \"Dictionary\" currently charges £21.28 per system. Change coding so that in future:
a. For each Fixed licence (input \"Type\" value=1), it should be’ £21.28 (as at present)
b. For’ each Floating licence (input \"Type\" value=1.6), it should be’ the greater of \"£21.28\" and \"5% of the boxed-system Floating-licence price\".

** Fiile won't attach; please go to http://www.sciword.demon.co.uk/lic-calcdevelopment.htm **