How do you know the scroll bar has reached bottom of a page

Question

I have a HTML page, when the scroll bar reaches bottom of the page I need to slide in a div from bottom-right containing an iframe.

Using JQuery I have implemented

Answer 1

You would to use the scroll function in jquery to check the position if it has reached document.height or window.height values. Something along the lines of this (I haven't verified it)

$(window).scroll(function(){ 
   console.log($(window).scrollTop() == ($(document).height() - $(window).height()));
})