$(document).ready(function(){
	
	/* This code is executed after the DOM has been completely loaded */
	var totWidth=0;
	var positions = new Array();
	
	$('#slides .slide').each(function(i){
		/* Traverse through all the slides and store their accumulative widths in totWidth */
		positions[i]= totWidth;
		totWidth += $(this).width();
		
		/* The positions array contains each slide's commulutative offset from the left part of the container */
		if(!$(this).width()){
			alert("Please, fill in width & height for all your images!");
			return false;
		}
	});
	$('#slides').width(totWidth);

	/* Change the cotnainer div's width to the exact width of all the slides combined */
	$('#menu ul li a').click(function(e,keepScroll){
		
		/* On a thumbnail click */
		$('li.menuItem').removeClass('act').addClass('inact');
		$(this).parent().addClass('act');
		
		var pos = $(this).parent().prevAll('.menuItem').length;
		
		/* Start the sliding animation */
		$('#slides').stop().animate({marginLeft:-positions[pos]+'px'},500);
		
		/* Prevent the default action of the link */
		e.preventDefault();
	
		/* Stopping the auto-advance if an icon has been clicked: */
		if(!keepScroll) clearInterval(itvl);
	});
	
	/* On page load, mark the first thumbnail as active */
	$('#menu ul li.menuItem:first').addClass('act').siblings().addClass('inact');
	

	/***Enabling auto-advance***/
	var current=1;
	function autoAdvance(){
		if(current==-1) return false;
		
		$('#menu ul li a').eq(current%$('#menu ul li a').length).trigger('click',[true]); //[true] will be passed as the keepScroll parameter of the click function on line 28
		current++;
	}

	/* The number of seconds that the slider will auto-advance in: */
	var changeEvery = 5;
	var itvl = setInterval(function(){autoAdvance()},changeEvery*1000);
});