So, you should have something like this (Additions or changes in bold):
<div id="themenu">
<script type='text/javascript'>
function Go(){return}
/***********************************************************************
YOU CAN MANUALLY CHANGE THE MENU HERE, BUT BE VERY CAREFUL !
***********************************************************************/
Menu1=new Array("Menu 1","","",3,20,80);
Menu1_1=new Array("Sub 1","#","",0,20,80);
Menu1_2=new Array("Sub 2","#","",0,20,0);
Menu1_3=new Array("Sub 3","#","",0,20,80);
Menu2=new Array("Menu 2","","",4,0,80);
Menu2_1=new Array("Sub 1","#","",0,20,80);
Menu2_2=new Array("Sub 2","#","",0,20,0);
Menu2_3=new Array("Sub 3","","",3,20,0);
Menu2_3_1=new Array("Sub Sub 1","#","",0,20,80);
Menu2_3_2=new Array("Sub Sub 2","#","",0,20,0);
Menu2_3_3=new Array("Sub Sub 3","#","",0,20,0);
Menu2_4=new Array("Sub 4","#","",0,20,0);
Menu3=new Array("Menu 3","#","",0,20,80);
Menu4=new Array("Menu 4","","",2,20,80);
Menu4_1=new Array("Sub 1","#","",0,20,80);
Menu4_2=new Array("Sub 2","#","",0,20,0);
var NoOffFirstLineMenus=4; // Number of first level items
var LowBgColor='#0080FF'; // Background color when mouse is not over
var LowSubBgColor='#0080FF'; // Background color when mouse is not over on subs
var HighBgColor='#009CE8'; // Background color when mouse is over
var HighSubBgColor='#009CE8'; // Background color when mouse is over on subs
var FontLowColor='#FFFFFF'; // Font color when mouse is not over
var FontSubLowColor='#FFFFFF'; // Font color subs when mouse is not over
var FontHighColor='#0000FF'; // Font color when mouse is over
var FontSubHighColor='#0000FF'; // Font color subs when mouse is over
var BorderColor='#000000'; // Border color
var BorderSubColor='#000000'; // Border color for subs
var BorderWidth=1; // Border width
var BorderBtwnElmnts=1; // Border between elements 1 or 0
var FontFamily="Tahoma, Verdana, Arial" // Font family menu items
var FontSize=10; // Font size menu items
var FontBold=0; // Bold menu items 1 or 0
var FontItalic=0; // Italic menu items 1 or 0
var MenuTextCentered='left'; // Item text position 'left', 'center' or 'right'
var MenuCentered='left'; // Menu horizontal position 'left', 'center' or 'right'
var MenuVerticalCentered='top'; // Menu vertical position 'top', 'middle','bottom' or static
var ChildOverlap=.2; // horizontal overlap child/ parent
var ChildVerticalOverlap=.2; // vertical overlap child/ parent
var StartTop=1; // Menu offset x coordinate
var StartLeft=1; // Menu offset y coordinate
var VerCorrect=0; // Multiple frames y correction
var HorCorrect=0; // Multiple frames x correction
var LeftPaddng=3; // Left padding
var TopPaddng=2; // Top padding
var FirstLineHorizontal=1; // SET TO 1 FOR HORIZONTAL MENU, 0 FOR VERTICAL
var MenuFramesVertical=1; // Frames in cols or rows 1 or 0
var DissapearDelay=1000; // delay before menu folds in
var TakeOverBgColor=1; // Menu frame takes over background color subitem frame
var FirstLineFrame='navig'; // Frame where first level appears
var SecLineFrame='space'; // Frame where sub levels appear
var DocTargetFrame='space'; // Frame where target documents appear
var TargetLoc='themenu'; // span (or div) id for relative positioning
var HideTop=0; // Hide first level when loading new document 1 or 0
var MenuWrap=1; // enables/ disables menu wrap 1 or 0
var RightToLeft=0; // enables/ disables right to left unfold 1 or 0
var UnfoldsOnClick=0; // Level 1 unfolds onclick/ onmouseover
var WebMasterCheck=0; // menu tree checking on or off 1 or 0
var ShowArrow=1; // Uses arrow gifs when 1
var KeepHilite=1; // Keep selected path highligthed
var Arrws=['tri.gif',5,10,'tridown.gif',10,5,'trileft.gif',5,10]; // Arrow source, width and height
/***********************************************************************
DO NOT EDIT ANYTHING BELOW THIS LINE - IT WILL BREAK THE SCRIPT !
***********************************************************************/
var AgntUsr=navigator.userAgent.toLowerCase();
var DomYes=document.getElementById?1:0;
var NavYes=AgntUsr.indexOf('mozilla')!=-1&&AgntUsr.indexOf('compatible')==-1?1:0;
var ExpYes=AgntUsr.indexOf('msie')!=-1?1:0;
var Opr=AgntUsr.indexOf('opera')!=-1?1:0;
var Opr6orless=window.opera && navigator.userAgent.search(/opera.[1-6]/i)!=-1 //DynamicDrive.com added code
if ( Opr6orless!=1 ) { ExpYes = 1 }
var DomNav=DomYes&&NavYes?1:0;
var DomExp=DomYes&&ExpYes?1:0;
...
...
...a whole bunch of code...
...
...
function BeforeStart(){return}
function AfterBuild(){return}
function BeforeFirstOpen(){return}
function AfterCloseAll(){return}
</script>
<noscript>Your browser does not support script</noscript>
<!-- REST OF BODY CONTENT BELOW HERE -->
</div>