var slideInterval 		= 3; // amount of time between slides in seconds

var currentSlide 		= 0;
var prevSlide 			= null;
var slides 				= $('.display_space .slide_show div');
var len 				= null;
var loop				= null;



function initSlideNav() {
	
	slides = $('.display_space .slide_show div');
	len = slides.length;

	if (len <= 1) return;
	
	
	
	// write list
	var list = '<ul>';
	for (var i=len-1; i >= 0; i--) {
		list += '<li id="slide_' + i + '"></li>';		
	};
	list += '</ul>';
	$('.display_space .slide_show_nav').append(list);
	
	// enable list
	for (i=len-1; i >= 0; i--) {
		if (i != currentSlide) {
			$(slides[i]).animate({opacity: 0}, 0);
		
		} else {
			$('#slide_'+i).addClass('selected');
		}
		
		$('#slide_'+i).bind("click",{index:i},function(event){
				if (loop) clearInterval(loop);
		        currentSlide = event.data.index;
		        gotoSlide(event.data.index);
		});
		
		
	}
	
	loop = setInterval( incrementSlide, slideInterval*2000 );
 	
	
	
}



function incrementSlide() {
    if (currentSlide >= len -1){
        currentSlide = 0;
    }else{
        currentSlide++;
    }

    gotoSlide(currentSlide);
	
}

function gotoSlide(slideNum) {
	
	if (slideNum != prevSlide) {

		if (prevSlide == null) prevSlide = 0;
	
		$(slides[prevSlide]).animate({opacity: 0}, 500,function() {
            $(slides[prevSlide]).removeClass('active last-active');
        });

		$('#slide_'+prevSlide).removeClass('selected');			
		

		$(slides[slideNum]).animate({opacity: 1.0}, 500).addClass('active');
		$('#slide_'+slideNum).addClass('selected');
	
		prevSlide = currentSlide;
		
	}
	
	

}

$(document).ready(function() {
	initSlideNav();
});