$(document).ready(function() {
    var $nav = $("#nav");
   	var $topbtn = ($("#topbtn"));
	  var $navlinks = $("#navcontainer a") ;
	  $topbtn.hide();
	  load();
   
  	jQuery(window).bind('scrollstop', function(e){
	  		scrollNow();
		});
    
});

 function load() {       
 var $nav = $("#nav");
 	var $topbtn = ($("#topbtn"));
  var $navlinks = $("#navcontainer a") ;
	$(".anchorLink").anchorAnimate();

	var jumpTo = $(window).scrollTop();  
	$nav.animate({top :  jumpTo},11);
    styleNav();

   
}   

function styleNav() {   
	var $nav = $("#nav");
 	var $topbtn = ($("#topbtn"));
  var $navlinks = $("#navcontainer a") ;
	var urllocation = window.location.hash;
	$navlinks.removeClass("active");
	if (urllocation == '#about') {
		$("#about-btn a").addClass("active");
	}    
	else if (urllocation == '#subjects') {
		$("#subjects-btn a").addClass("active");
	}
	else if (urllocation == '#contact') {
		$("#contact-btn a").addClass("active");
	}
	else {
		$("#home-btn a").addClass("active");			 	
	}
   

}

  function scrollNow() {  
	  var $nav = $("#nav");
   	var $topbtn = ($("#topbtn"));
	  var $navlinks = $("#navcontainer a") ;
    var jumpTo = $(window).scrollTop();  
  	$nav.stop().animate({top :  jumpTo},211);

 	    styleNav(); 
	
}
  

 /*******

	***	Anchor Slider by Cedric Dugas   ***
	*** Http://www.position-absolute.com ***
	
	Never have an anchor jumping your content, slide it.

	Don't forget to put an id to your anchor !
	You can use and modify this script for any project you want, but please leave this comment as credit.
	
*****/ 

	
	jQuery.fn.anchorAnimate = function(settings) {

	 	settings = jQuery.extend({
			speed : 1100
		}, settings);	

		return this.each(function(){
			var caller = this
			$(caller).click(function (event) {	
				event.preventDefault()
				var locationHref = window.location.href
				var elementClick = $(caller).attr("href")
        var $topbtn = ($("#topbtn")); 
				var destination = $(elementClick).offset().top;
				$("html:not(:animated),body:not(:animated)").animate({ scrollTop: destination}, settings.speed, function() {
					window.location.hash = elementClick;
					styleNav();
					if ($(elementClick).offset().top != "0") {
						$topbtn.show();
					}
					else {
						$topbtn.hide();
					}
				});
			  	return false;
			})
		})
	}