The webpage generated by SpreadsheetConverter is very clean and structured and can easily be integrated with other JavaScript code. We integrated the mortgage-calculator with the graphs package of Netscape in order to create live charts directly on a webpage.
This information is obsolete. Version 3 creates live 2d-charts automatically.
A soon as you leave a field, all values will be calculated and the chart will be updated. If you enter illegal values like a negative amount, the calculator will warn the user.
Test it right away, change the number of year and the chart will update itself immediately.
In order to do this you should be used to HTML and JavaScript. Read how to do this yourself here.