Scrolling

<script type='text/javascript'>
<!--
// Parameter
var sense1 = 30; // Scroll zone 1 (in %)
var sense2 = 15; // Scroll zone 2 (in %)
var speed1 = 5; // Scrollspeed in Zone 1
var speed2 = 20; // Scrollspeed in Zone 2
var stime = 10; // Timer for Scrolling

// Internal Variables
var scrolling = false;
var scrollfast;
var richtung;
var y_mem = -1;
var myWin;

// Stop Scrolling
function stopp_scrolling()
{
scrolling = false;
y_mem = -1;
}

// Scroll aktivate and initial
function start_scrolling(initial)
{
if(!scrolling)
return;

// Determine Position
var dy = (myWin.pageYOffset != null) ? myWin.pageYOffset : myWin.document.body.scrollTop;
if((y_mem != dy) && !initial)
return;
var dx = (myWin.pageXOffset != null) ? myWin.pageXOffset : myWin.document.body.scrollLeft;
dx += richtung * (scrollfast ? speed2 : speed1);

// Scroll
myWin.scrollTo(dx, dy);
y_mem = dy;

// Initial function again
setTimeout("start_scrolling(false)", stime);
}

// Analysis of Mouse Position
function zeige(e)
{
// Mouse Position and Document Data
var y = myWin.Event ? e.pageX : myWin.event.clientX;
if(myWin.Event)
y -= - (myWin.pageXOffset != null) ? myWin.pageXOffset : myWin.document.body.scrollTop;
var wh = myWin.innerWidth ? myWin.innerWidth : myWin.document.body.clientWidth;
var dh = myWin.document.height ? myWin.document.height : myWin.document.body.scrollHeight;

// Variables
var s1 = Math.round(wh * sense1 / 100);
var s2 = Math.round(wh * sense2 / 100);
var now_scroll;

// Determine necessity to Scroll
if((y < s1) || (y > (wh - s1)))
{
now_scroll = true;
richtung = (y < s1) ? -1 : 1;
scrollfast = ((y < s2) || (y > (wh - s2))) ? true : false;
}
else
{
now_scroll = false;
scrolling = false;
}

// Scroll Status changed?
if(now_scroll != scrolling)
{
y_mem = -1;
scrolling = now_scroll;
if(scrolling)
start_scrolling(true);
}
}

// Initiate Mouse Control
function init()
{
myWin = window;

if(myWin.Event)
myWin.document.captureEvents(Event.MOUSEMOVE);

myWin.document.onmousemove = zeige;
}
if(window.focus) window.focus();
document.onblur = stopp_scrolling();
//-->

window.onload=init;
</script>