javascript reach bottom of page
function getDocHeight() { // $(document).height() value depends on browser
var D = document;
return Math.max(
D.body.scrollHeight, D.documentElement.scrollHeight,
D.body.offsetHeight, D.documentElement.offsetHeight,
D.body.clientHeight, D.documentElement.clientHeight
);
}
$(window).scroll(function() {
if($(window).scrollTop() + $(window).height() == getDocHeight()) {
alert("bottom!");
}
});