window.onload = function(){	
	$('body').addClass('js');
	
	initDemopageSlides();
}
function initDemopageSlides(){
	demo_slide_animation_speed = 800;
	demo_slide_animation_timeout = 4000;
	if($('.demo_slide').length <= 1) return;
	$("#slide_next").click(onSlideNextClick);
	$("#slide_prev").click(onSlidePrevClick);
	var first_slide = $(".demo_slide:first");
	first_slide.addClass("current");
	var zIndexNumber = 100;	
	$('.demo_slide').each(function() {
	$(this).css('zIndex', zIndexNumber);
	zIndexNumber -= 1;
	});
	onSlideAnimationComplete();
}
function shuffleArray(v){
    for(var j, x, i = v.length; i; j = parseInt(Math.random() * i), x = v[--i], v[i] = v[j], v[j] = x);
    return v;
};
function onSlideNextClick(event){
	navigateSlides(1);
}
function onSlidePrevClick(event){
	navigateSlides(-1);
}
function navigateSlides(distance){	
	clearTimeout(time_out);
	if(animationInProgress) return;
	var slides_arr = $(".demo_slide");
	for(var s=0; s < slides_arr.length; s++){
		if($(slides_arr[s]).hasClass("current")){
			var previous_slide = $(slides_arr[s]);
			previous_slide.removeClass("current");
			break;	
		}
	}
	var next_index = s + distance;
	if(next_index < 0) next_index += slides_arr.length;
	if(next_index >= slides_arr.length) next_index = 0;
	var next_slide = $(slides_arr[next_index]);
	next_slide.addClass("current");
	var previous_zIndex = $(previous_slide).css('zIndex');
	next_slide.css('zIndex', Number(previous_zIndex) + 10);
	animationInProgress = true;
	var slide_width = parseFloat(next_slide.css("width"));
	next_slide.css(next_index%2?"right":"left",(slide_width * distance)/4 + "px");
	next_slide.css("display","block");
	next_slide.css("opacity","0");
	if(next_index%2){
		next_slide.animate( {right:0, opacity:1}, demo_slide_animation_speed, onSlideAnimationComplete);
	} else {
		next_slide.animate( {left:0, opacity:1}, demo_slide_animation_speed, onSlideAnimationComplete);	
	}
}
function onSlideAnimationComplete(){
	animationInProgress = false;
	time_out = setTimeout (onSlideNextClick,demo_slide_animation_timeout);
}