Mortgage calculator script

We want to have a script to calculate the mortgage payment in our website. It need to be a custom one and here are the information that we need. It need to have a case for House price, Down Payment Interest rate, Loan term, start date. It will need to load another page once the person will hit the button to caculate the payment. On the second page we will see the result like a summary. - Monthly payment - Total payment for this amount - Total interest paid - Pay-off Date Something similar to what amortization-calc dot com has. Thank you Bobby