Which page in an xml data-bound table

I have an HTML table (I set datapagesize=10)bound to an XML data island (with about 100 nodes). I also have navigation (First, Prev, etc) buttons for browsing the XML data 10 rows at a time. How do I determine which page I’m currently looking at, and how many pages there are (using JavaScript? I want to be able to say “Page X of Y pages”, where X represents the current page, and Y is the number of pages.
Thanks.