php scroll der hopper

Hey. Jeg har en kode til et et par scrollknapper der ser sådan her ud:
<div id="staticbuttons" style="position:absolute; width: 108; height: 53;"> <a href="java script:" onmouseover="myspeed=-thespeed" onmouseout="myspeed=0"><img
src="billeder/pilOp.gif" border="0" align="left" /></a> <a href="java script:" onmouseover="myspeed=thespeed" onmouseout="myspeed=0"><img
src="billeder/pilNed.gif" border="0" /></a> </div>
              <script>

//Page Scroller (aka custom scrollbar)- By Dynamic Drive
//For full source code and more DHTML scripts, visit http://www.dynamicdrive.com
//This credit MUST stay intact for use

var Hoffset=124 //Enter buttons' offset from right edge of window (adjust depending on images width)
var Voffset=360 //Enter buttons' offset from bottom edge of window (adjust depending on images height)
var thespeed=3 //Enter scroll speed in integer (Advised: 1-3)

var ieNOTopera=document.all&&navigator.userAgent.indexOf("Opera")==-1
var myspeed=0

var ieHoffset_extra=document.all? 15 : 0
var cross_obj=document.all? document.all.staticbuttons : document.getElementById? document.getElementById("staticbuttons") : document.staticbuttons

function iecompattest(){
return (document.compatMode && document.compatMode!="BackCompat")? document.documentElement : document.body
}

function positionit(){
var dsocleft=document.all? iecompattest().scrollLeft : pageXOffset
var dsoctop=document.all? iecompattest().scrollTop : pageYOffset
var window_width=ieNOTopera? iecompattest().clientWidth+ieHoffset_extra : window.innerWidth+ieHoffset_extra
var window_height=ieNOTopera? iecompattest().clientHeight : window.innerHeight

if (document.all||document.getElementById){
cross_obj.style.left=parseInt(dsocleft)+parseInt(window_width)-Hoffset+"px"
cross_obj.style.top=dsoctop+parseInt(window_height)-Voffset+"px"
}
else if (document.layers){
cross_obj.left=dsocleft+window_width-Hoffset
cross_obj.top=dsoctop+window_height-Voffset
}
}

function scrollwindow(){
window.scrollBy(0,myspeed)
}

function initializeIT(){
positionit()
if (myspeed!=0){
scrollwindow()
}
}

if (document.all||document.getElementById||document.layers)
setInterval("initializeIT()",20)

        </script>

Og i praksis ser det sådan her ud:
http://viccer.com/Viccer/guestbookFrame.php

Mit problem er, at hvis man kører musen hen over pilene så "hopper" de lidt op og ned.. (men de virker)
Jeg ville høre om nogle af jer ved om det er noget i koden der gør at de hopper, og om der er en måde at få dem til at blive på deres plads..

MVH Viccer