var DROP_DOWN_MENU_TOP = 129;





function DNode(title, text, img){
	this.title = title;
	this.text = text;
	this.img = img;
	this.next = null;
	this.previous = null;
}


function DLList(){
	this.root = null;
	this.title="";
	this.insert = function(title, text, img){
		var new_node = new DNode(title, text, img)
		if(this.root == null){//if first element
			this.root = new_node;
			this.root.next = this.root;
			this.root.previous = this.root;
		}else{
			new_node.next = this.root;
			new_node.previous = this.root.previous;
			this.root.previous.next = new_node;
			this.root.previous = new_node;
			this.root = new_node;
		}
	}
	this.next = function(){ this.root = this.root.next;}
	this.previous = function(){ this.root = this.root.previous;}
	
	this.get_img = function(){ return this.root.img;}
	this.get_title = function(){ return this.root.title;}
	this.get_text = function(){ return this.root.text;}
}

function News_Ticker(tick_rate, title_div, text_div){
	this.tick_rate = tick_rate;
	this.title_div = title_div;
	this.text_div = text_div;
	this.stories = new DLList();
	this.tick_index = 1;//on

	this.add_story = function(title, text, img_div){ 
		this.stories.insert(title, text, img_div);
		this.draw();
	}	
	this.next = function(){
		this.hide_background();
		this.stories.next();
		this.draw();
		this.show_background();
	}
	this.previous = function(){
		this.hide_background();
		this.stories.previous();
		this.draw();
		this.show_background();
	}
	this.hide_background = function(){
		document.getElementById(this.stories.get_img()).style.visibility = "hidden";		
	}
	this.show_background = function(){
		document.getElementById(this.stories.get_img()).style.visibility = "visible";		
	}
	this.draw = function(){
		var current;
		var new_image = document.createElement('img');
		new_image.src = this.stories.root.img;
		
		current = document.getElementById(this.title_div);
		current.innerHTML = this.stories.get_title();
		current = document.getElementById(this.text_div);
		current.innerHTML = this.stories.get_text();
	};
	this.tick = function(self){
		if(ticker.tick_index > 0){
			self.next();
			var p = window.setTimeout("ticker.tick(ticker)", self.tick_rate);		
		}else
			var p = window.setTimeout("ticker.tick(ticker)", self.tick_rate);		
	};
	this.pause = function(){
		if(this.tick_index<0){
			//play
			this.tick_index = 20;
			document.getElementById('play_img').style.visibility="hidden";			
			document.getElementById('pause_img').style.visibility="visible";

		}else{
			//pause
			this.tick_index= -1;
			document.getElementById('pause_img').style.visibility="hidden";			
			document.getElementById('play_img').style.visibility="visible";

		}
	};
}



function sleep(Us){
	var waitFlag = true;
	var p = window.setTimeout("waitFlag=false", Us);
	while(waitFlag){;}
}




function all_off(){
	document.getElementById('nav3_menu').style.visibility = "hidden";
	document.getElementById('nav4_menu').style.visibility = "hidden";
	document.getElementById('nav5_menu').style.visibility = "hidden";
	document.getElementById('nav6_menu').style.visibility = "hidden";
}

function draw_menu(div_id){
	///DRAW MENU DOES NOT MAKE THE MENU VISIBLE
	var parent=document.getElementById(div_id);
	var menu=document.getElementById(div_id + "_menu");
	var winW=0;
	var winCenter=0;
	var left=0;


	//find winCenter
	if (parseInt(navigator.appVersion)>3) {
		if (navigator.appName=="Netscape") { winW = window.innerWidth;}
		if (navigator.appName.indexOf("Microsoft")!=-1) { winW = document.body.offsetWidth;}
	}
	winCenter = winW / 2;

	//calculate respective nav_bar locations	
	if(div_id.toString() == 'nav3') left = winCenter - 225;	//site selectors
	if(div_id == 'nav4') left = winCenter - 150; 			//learning
	if(div_id == 'nav5') left = winCenter - 100;			//living
	if(div_id == 'nav6') left = winCenter - 40;				//working

	document.getElementById(div_id + "_menu").style.top = DROP_DOWN_MENU_TOP + "px";
	document.getElementById(div_id + "_menu").style.left = left + "px";
}

function mouse_over(div_id){
	all_off();
	if(div_id.toString() != "kill"){
		draw_menu(div_id);
		document.getElementById(div_id + "_menu").style.visibility = "visible";
	}
}


function mouse_out(){}

function resize_handler(){
	draw_menu('nav3');
	draw_menu('nav4');
	draw_menu('nav5');
	draw_menu('nav6');
}

function Set_Cookie( name, value, expires, path, domain, secure ) 
{
	// set time, it's in milliseconds
	var today = new Date();
	today.setTime( today.getTime() );
	
	/*
	if the expires variable is set, make the correct 
	expires time, the current script below will set 
	it for x number of days, to make it for hours, 
	delete * 24, for minutes, delete * 60 * 24
	*/
	if ( expires )
	{
	expires = expires * 1000 * 60 * 60 * 24;
	}
	var expires_date = new Date( today.getTime() + (expires) );
	
	document.cookie = name + "=" +escape( value ) +
	( ( expires ) ? ";expires=" + expires_date.toGMTString() : "" ) + 
	( ( path ) ? ";path=" + path : "" ) + 
	( ( domain ) ? ";domain=" + domain : "" ) +
	( ( secure ) ? ";secure" : "" );
}

function set_section_cookie(section){
	Set_Cookie( 'section', section, new Date().getFullYear() + 60) ;
}