$(document).ready(function() {
	frontpage_image_resize();
	$(window).resize(frontpage_image_resize);
});

function frontpage_image_resize() {
	var frontpage_image = $("#frontPageImage img");
	var w = frontpage_image.attr("width");
	var h = frontpage_image.attr("height");
	var r = w/h;
	var window_w = $(window).width();
	var window_h = $(window).height();
	var window_r = window_w/window_h;
	var new_w; var new_h;
	if (window_r >= r) {
		new_w = window_w;
		new_h = window_w/r;
	} else {
		new_w = window_h*r;
		new_h = window_h;
	}
	frontpage_image.attr("width", new_w);
	frontpage_image.attr("height", new_h);
	if(window_w < new_w) {
        offset = (new_w - window_w) / 2;
        $("#frontPageImage img").css({'margin-left': '-'+offset+'px'});
    } else {
        $("#frontPageImage img").css({'margin-left': '0px'});
    }
}