Online Pace Calculator

I am looking for a simple marathon pace calculator. If you check the web, there are TONS of them out there, but I don't like how any of them look. What I would like is a "slider" for pace and time. If you slide across the pace, it will drag the time with it. Or if you change the pace, the time will move. Everything I see online is typically you typing in a pace or time and it will show you the results. Take a look at this as a basic example of what I am looking for. This is NOT a calculator, but it shows you how the things slide on the website and the numbers change below based on the movement. I have attached a very rough view of what I am requesting to help you bid on the project. I will provide very detailed specifications to the winning bidder. [login to view URL] Please let me know what you would develop this in and if you have a way to protect it from people copying it online.