skyOffset = 0;
function stickySkyscraper() {
	var footerMargin = 10;
	var blockHeight = 600;
	var blockMarginTop = 10;
	
	$(window).load(function() {
		if ($("#skyscraper").length) {
			// original location
			skyOffset = $("#skyscraper").offset().top;
			
			$(window).scroll(function() {
				blockHeight = $("#skyscraper").height();
				
				var marginTop = window.scrollY - skyOffset + blockMarginTop;
				var maxY = $("#footer").offset().top - footerMargin;
				
				// scrolled down enough
				if (marginTop > 0) {
					if (marginTop < maxY - blockHeight - skyOffset) {
						$("#skyscraper").css('margin-top', '' + (marginTop) + 'px');
					} else {
						$("#skyscraper").css('margin-top', '' + (maxY - blockHeight - skyOffset) + 'px');
					}
				} else {
					$("#skyscraper").css('margin-top', '0');
				}
			});
		}
	});
}

rectOffset = 0;
function stickyDoubleRect() {
	var footerMargin = 10;
	var blockHeight = 625;
	var blockMarginTop = 10;
	
	$(window).load(function() {
		if ($("#doublerect").length) {
			// original location
			rectOffset = $("#doublerect").offset().top;
			
			$(window).scroll(function() {
				blockHeight = $("#doublerect").height();
				
				var marginTop = window.scrollY - rectOffset + blockMarginTop;
				var maxY = $("#footer").offset().top - footerMargin;
				
				// scrolled down enough
				if (marginTop > 0) {
					if (marginTop < maxY - blockHeight - rectOffset) {
						$("#doublerect").css('margin-top', '' + (marginTop) + 'px');
					} else {
						$("#doublerect").css('margin-top', '' + (maxY - blockHeight - rectOffset) + 'px');
					}
				} else {
					$("#doublerect").css('margin-top', '0');
				}
			});
		}
	});
}