$(document).ready(function(){

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

$('section[data-type="background"]').each(function(){
    // declare the variable to affect the defined data-type
    var $scroll = $(this);

    $(window).scroll(function() {
        // HTML5 proves useful for helping with creating JS functions!
        // also, negative value because we're scrolling upwards
        var yPos = -($window.scrollTop() / $scroll.data('speed'));

        // background position
        var coords = '50% '+ yPos + 'px';

        // move the background
        $scroll.css({ backgroundPosition: coords });
    }); // end window scroll
});  // end section function

}); // close out script

Create HTML5 element for IE

document.createElement(“section”);