// JavaScript Document
var target;
var target_old;

var distance;
var direction;

var moveTime;

function openpopup(url,name,options,fullscreen)
{
	windowobj = window.open(url,name,options);
	windowobj.focus();
	return false;
}

function init() {
	target_old = 150; 		//fenster hat sich nicht bewegt
	moveTime = 15;				//wie schnell wird gewandert
	
	//
	Listener();	
	window.setTimeout("Mover()", moveTime);
}

function Listener() {
	if (document.documentElement && document.documentElement.scrollTop) {
	//http://www.quirksmode.org/js/doctypes.html
	
		target = document.documentElement.scrollTop;
	} else if (document.body) {
		target = document.body.scrollTop
	} else {
		target = window.pageYOffset;
	}
	
	//+150px vom oberen Rand
	target = target + 150;
	
	if(target != target_old) {
		//Ziel umspeichern
		//
		if(target < target_old) {
			distance = target_old - target;
			direction = "up";	
		} else {
			distance = target - target_old;
			direction = "down";
		}
	}
	
	window.setTimeout("Listener()", 250);	
	
}


function Mover() {
	
	//if(distance < 10) {
//		step = 1;
//	} else if (distance < 100) {
//		step = 5;
//	} else if (distance <400) {
//		step = 15;
//	} else {
//		step = 20;
//	}
	if(distance < 6) {
		step = 1;
	} if(distance < 24) {
		step = 3;
	} else if (distance < 54) {
		step = 5;
	} else if (distance <144) {
		step = 15;
	} else {
		step = 20;
	}
	distance = distance - step;
	
	//dem Ziel nähern
	if(direction =="up") {
		if(target_old > target) { 
			target_old = target_old - step;
		} else {
			target_old = target;
		}
	} else {
		if(target_old < target) {
			target_old = target_old + step;
		} else {
			target_old = target;
		}
	}
	
	if(document.all && document.all.menu.style.setAttribute) {
		document.all.menu.style.setAttribute("top", target_old + "px", "false");
	} else {
		document.getElementById("menu").style.top = target_old + "px";	
	}	
	window.setTimeout("Mover()", moveTime);	
}