A good example of one such working calculator with the functionality I need can be found here: [url removed, login to view]
I have also attached a mock-up of the design I am looking for. Here are a few specifics:
1. Width: 580 pixels.
2. Font: Tahoma.
3. Color: 00539B with white background.
Lastly, please address me as "Matt" in you bid so that I know that you have taken the time to read and understand this project.