$(document).ready(function() {
	
	if($('#home_content').is(':visible')) {
		var welcome_pos = $('#home_content').offset().top;
		var about_pos = $('#about_content').offset().top;
		var services_pos = $('#services_content').offset().top;
		var products_pos = $('#products_content').offset().top;
		var references_pos = $('#references_content').offset().top;
		var contact_pos = $('#contact_content').offset().top;
		$(window).scroll(function() {
			var wp = $(window).scrollTop();
			$('#nav li a').removeClass('selected');
			if(wp >= welcome_pos && wp < about_pos) {
				$('#home_toggle').addClass('selected');
			}else if(wp >= about_pos && wp < services_pos) {
				$('#about_toggle').addClass('selected');
			}else if(wp >= services_pos && wp < products_pos) {
				$('#services_toggle').addClass('selected');
			}else if(wp >= products_pos && wp < references_pos) {
				$('#products_toggle').addClass('selected');
			}else if(wp >= references_pos && wp < contact_pos) {
				$('#references_toggle').addClass('selected');
			}else if(wp >= contact_pos) {
				$('#contact_toggle').addClass('selected');
			}
		});
	}
	
});