var old_content = "";
var content_index = -1;
var total_content;

jQuery.noConflict();

jQuery(document).ready(function(){
	initNav();
	total_content = jQuery(".subcontent").length;
	
	var pn = 1;
	if(document.location.hash.length){
		pn = parseInt(document.location.hash.split("#")[1]);
		if(pn < 1 || pn > total_content) pn=1;
	}
	showContent(pn);
});

function initNav()
{
	jQuery(".submenus").find("a").attr("href", "javascript:;")		// add events on sub menu
	jQuery(".submenus").find("a").click(function(){ showContent(extractId(this.id)); });
	
	jQuery("#subnav_prev").css("visibility", "hidden");				// next/prev arrows
	jQuery("#subnav_next").css("visibility", "visible");
	jQuery("#subnav_prev").click(function(){prevcontent()});	
	jQuery("#subnav_next").click(function(){nextcontent()});	
}

function showContent(id)
{
	if(id == old_content) return;
	
	var content_id = "subcontent_"+id
	hideContent("subcontent_"+old_content)	// hide old content
	jQuery("#"+content_id).slideDown(1000);		// show new content
	
	jQuery("#subnav_"+old_content).removeClass("submenuson");
	jQuery("#subnav_"+id).addClass("submenuson");
	
	content_index = parseInt(id);
	old_content = id;
	
	// show/hide prev and next buttons
	if(content_index > 1) {
		jQuery("#subnav_prev").css("visibility", "visible");
	} else {
		jQuery("#subnav_prev").css("visibility", "hidden");
	}
	if(content_index < total_content) {
		jQuery("#subnav_next").css("visibility", "visible");
	} else {
		jQuery("#subnav_next").css("visibility", "hidden");
	}
	
	document.location.hash = content_index;
}

function hideContent(id)
{
	//if(!old_content.length) return;
	jQuery("#"+id).slideUp(500);
}

function extractId(long_id) 	//long_id" -> "id"
{
	return long_id.split("_")[1];
}

function prevcontent()
{
	content_index--;
	if(content_index < 1) content_index = total_content;
	showContent(content_index);
}
function nextcontent() 
{
	content_index++;
	if(content_index > total_content) content_index = 1;
	showContent(content_index);
}