Breaks on window resize

[marcelklehr]

FF10 on Win

[ehmorris]

fixed - the divisor constant was breaking because the birdseye container's top offset was meant to be its offset from the top of the window rather than the top of the document.

birdseye_constants.divisor = $(document).height() / 
                            ($(window).height() - $('.birdseye').offset().top);

$(window).height() - $('.birdseye').offset().top was producing a negative number

Changed to:

birdseye_constants.divisor = $(document).height() / 
                            ($(window).height() - ($('.birdseye').offset().top - window.scrollY));