// Based on findPos*, by ppk (http://www.quirksmode.org/js/findpos.html)
function findPosX(obj) {
	var curLeft = 0;
	if (obj.offsetParent) {
		do {
			curLeft += obj.offsetLeft;
		} while (obj = obj.offsetParent);
	}
	else if (obj.x) {
		curLeft += obj.x;
	}
	return curLeft;
}

function findPosY(obj) {
	var curTop = 0;
	if (obj.offsetParent) {
		do {
			curTop += obj.offsetTop;
		} while (obj = obj.offsetParent);
	}
	else if (obj.y) {
		curTop += obj.y;
	}
	return curTop;
}

// cross-browser event handling for IE5+, NS6+ and Mozilla/Gecko
// By Scott Andrew
function addEvent(obj, evType, fn, useCapture) {
	if (obj.addEventListener) {
		obj.addEventListener(evType, fn, useCapture);
	return true;
	} 
	else if (obj.attachEvent) {
		var r = obj.attachEvent('on' + evType, fn);
		return r;
	} 
	else {
		obj['on' + evType] = fn;
	}
}

var isIE = !window.opera && navigator.userAgent.indexOf('MSIE') != -1;

addEvent(window, 'load', scrollInit, false);

function scrollInit() {
	if (!document.getElementById)
	return;
	var tub = document.getElementById('tub');
	addEvent(tub, 'mousemove', moveListener, false);
	document.getElementById('tapa').style.display='none';
}
function moveListener(ev) {
	var e = window.event ? window.event : ev;
	var t = e.target ? e.target : e.srcElement;
	
	var mX, mY;
	if (e.pageX && e.pageY) {
		mX = e.pageX;
		mY = e.pageY;
	} 
	else if (e.clientX && e.clientY) {
		mX = e.clientX;
		mY = e.clientY;
		if (isIE) {
			mX += document.body.scrollLeft;
			mY += document.body.scrollTop;
		}
	}

	var xPos = mX - findPosX(t);
	var yPos = mY - findPosY(t);
	tu = document.getElementById('tub');
	t = document.getElementById('fot');
	var theight = (t.height);
	var twidth = (t.width);
	var tuheight = (tu.height+2);
	var tuwidth = (tu.width+2);
	var aa = (isIE)?400 + ((theight)/(tuheight)):400;
	var bb = (isIE)?500 + ((twidth)/(tuwidth)):500;
	
	var scaleFactorY = ((theight) - aa)  / (tuheight);
	var scaleFactorX = ((twidth) - bb) / (tuwidth);

	t.style.left = (-parseInt(xPos * scaleFactorX)) + 'px ';
	t.style.top = (-parseInt(yPos * scaleFactorY)) + 'px';
}