ecurrencies exchange script

I need an ecurrency script like this one here: [login to view URL] and a demo can be found here: [login to view URL] Please note that i don't need all the functions like register/login...etc The script must be very easy. It must have the calculation of costs based on the input data, meaning..the user wants to exchange 100$ from to and it calculates the costs like on the example page. Then user is sent to a page based on the wallet selected where it tells him where to send the money. After that he can click on a button that says confirm payment and that's it. I need this very very fast ASAP. Only for people who already did this. If you can't show me an example of this don't bid please. I don't have time to waist.