Ajax Availability Calendar

Is there anyway to see this added to the default file, I kept trying but would always break the calendar showing up. I want to use the link function, but am unsure where the new call to draw the calendar is.

I was wondering if you have thought about somehow integrating the calendar with a date selector. Where you could pass variables (start and end date) and check to see if the dates are free. After that, store them in a post parameter and pass them to a form?