$(document).ready(function() {  
						   
				
						   
function isScrolledIntoView(elem) {
var docViewTop = $(window).scrollTop();
var docViewBottom = $(window).scrollTop() + 136;

var elemTop = $(elem).offset().top;
var elemBottom = elemTop + $(elem).height() + 137;
return ((elemBottom >= docViewTop) && (elemTop <= docViewBottom));
}

 $("#nav ul li:first-child").addClass("current");

 $(window).scroll(function() {
 if(isScrolledIntoView('#home')) {
 $('#nav li').siblings().removeClass("current");
 $("#home-btn").addClass('current');
 }

 if(isScrolledIntoView('#units')) {
 $('#nav li').siblings().removeClass("current");
 $("#units-btn").addClass('current');
 }

 if(isScrolledIntoView('#storage_tips')) {
 $('#nav li').siblings().removeClass("current");
 $("#storage_tips-btn").addClass('current');
 }

 if(isScrolledIntoView('#contact')) {
 $('#nav li').siblings().removeClass("current");
 $("#contact-btn").addClass('current');
 }

 });
 
}); 







/* Change Active state depending on scroll location */