Form - Price Quote Script

Hi All. I am looking for something that can take numeric values from the "value" attribute (or however you choose to do it) of a dropdown box or checkbox and add these to another field (a total field) in realtime. The finished project does not need to have a design, it can be some commented boxes on a page just to give me an idea of how it works. The script should be able to calculate the total price, send it to a email address embedded in the script, and a email address specified by the user. I would like to integrate with a shopping cart like oscommerce so let me know your ideas on that. PHP and flash are preferred but javascript is also accepted. This is a really simple job, so I've set a small budget. ---- Please leave a small description of HOW you would write this script - eg. what language you would use. Thanks!