$(document).ready(function(){
	var browheight = $(window).height();
	var browwidth = $(window).width();
	var headermarleft = ((2560-browwidth)/2)*-1;
	$(".header").css('margin-left', headermarleft+'px').css('margin-right', headermarleft+'px');	
	$(window).resize(function() {
		browheight = $(window).height();
		browwidth = $(window).width();
		headermarleft = ((2560-browwidth)/2)*-1;
		$(".header").css('margin-left', headermarleft+'px').css('margin-right', headermarleft+'px');
	});
});