// JavaScript Document
var slide_img_id = -1;

function set_opacity(slide_prefix, slide_id, opacity){
	var object = document.getElementById(slide_prefix + slide_id).style;
	
	if(opacity > 0) object.display = "block";
	
	object.opacity = (opacity / 100);
	object.MozOpacity = (opacity / 100);
	object.KhtmlOpacity = (opacity / 100);
	object.filter = "alpha(opacity=" + opacity + ")";
	
	if(opacity == 0) object.display = "none";
}

function fade_in(slide_prefix, slide_id, fade_in_seconds){
    var speed = Math.round((fade_in_seconds * 1000) / 100);
	
	for(i = 0; i <= 100; i++){
		setTimeout("set_opacity('" + slide_prefix + "', " + slide_id + ", " + i + ")", (i * speed));
	} 
}

function fade_out(slide_prefix, slide_id, fade_in_seconds){
    var speed = Math.round((fade_in_seconds * 1000) / 100);
	
	for(i = 0; i <= 100; i++){
		setTimeout("set_opacity('" + slide_prefix + "', " + slide_id + ", " + (100 - i) + ")", (i * speed));
	} 
}

function slideshow(slide_prefix, slide_count, slide_id, secs_to_display, secs_to_fade){	
	if(slide_imgs.length < 5){
		return 0;
	}
	if(slide_id <= 4){
		setTimeout("fade_out('" + slide_prefix + "', " + slide_id + ", " + secs_to_fade + ")", (secs_to_display * 1000));
		setTimeout("load_next_slide(" + slide_id + ")", ((secs_to_display + secs_to_fade + 2) * 1000));
	} else {
		setTimeout("fade_in('" + slide_prefix + "', " + (slide_id - 4) + ", " + secs_to_fade + ")", (secs_to_display * 1000));
		setTimeout("load_next_slide(" + slide_id + ")", ((secs_to_display + secs_to_fade + 2) * 1000));
	}
	
	slide_id++;
	if(slide_id > slide_count) slide_id = 1;

	setTimeout("slideshow('" + slide_prefix + "', " + slide_count + ", " + slide_id + ", " + secs_to_display + ", " + secs_to_fade + ")", ((secs_to_display + secs_to_fade) * 1000));
}

function load_next_slide(slide_id){
	if(slide_img_id == -1){ //set for the first time
		if(slide_imgs.length >= 8){
			slide_img_id = 7;
		} else {
			slide_img_id = ((8 % slide_imgs.length ) - 1);
		}
	}			
	
	slide_img_id++;
	if(slide_img_id > (slide_imgs.length - 1)) slide_img_id = 0;
	
	document.getElementById('pic' + slide_id).src = "/images/slideshow/" + slide_imgs[slide_img_id] + ".jpg";
}