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$(function(){

	//cache the window object
	var $window = $(window);

	//parallax background effect
	$('section[data-type="background"]').each(function(){
		var $bgobj = $(this); //assign the object

		$(window).scroll(function(){
			//scroll the background @ var speed
			// y negative because scrolling it up
			var yPos = - ($window.scrollTop() / $bgobj.data('speed'));
			//put together final background position
			var coords = '50%' + yPos + 'px';
			//move the background
			$bgobj.css({backgroundPosition:coords});
		});// end window scroll
	});

});

#hero {
	background: url('../img/hero-bg.jpg') 50% 0 repeat fixed;
	min-height: 500px;
	position: relative;
	display: table;
	width: 100%;
	padding: 40px 0;
	color: white;
	-webkit-font-smoothing: antialiased;
	text-rendering: optimizelegibility;
}

<section id="hero" data-type="background" data-speed="5">

</section>