$(document).ready(function() {
	
	resizeWindow();
	
	function resizeWindow() {
		var windowHeight = $(window).height();
		var wrapHeight = $("#wrap").height();
		var topMargin = (windowHeight - wrapHeight)/2;
		
		$("#wrap").css({
			marginTop:topMargin
		});
	}
	
	$(window).resize(resizeWindow);
			
});