browser_name = navigator.appName; 
browser_version = parseFloat(navigator.appVersion); 

if (browser_name == "Netscape" && browser_version >= 3.0) { roll = 'true'; } 
else if (browser_name == "Microsoft Internet Explorer" && browser_version >= 3.0) { roll = 'true'; } 
else { roll = 'false'; } 

function over(img,ref) { if (roll == 'true') { document.images[img].src = ref; } } 
function out(img,ref)  { if (roll == 'true') { document.images[img].src = ref; } } 

if (roll == 'true') 
{ 
a1=new Image;a1.src="images/menu/tek.gif"; 
a2=new Image;a2.src="images/menu/tek_r.gif"; 
a3=new Image;a3.src="images/menu/dia.gif";
a4=new Image;a4.src="images/menu/dia_r.gif";
a5=new Image;a5.src="images/menu/price.gif";
a6=new Image;a6.src="images/menu/price_r.gif";
a7=new Image;a7.src="images/menu/cont.gif";
a8=new Image;a8.src="images/menu/cont_r.gif";
} 

function alpha(obj,opacity){
obj.filters.alpha.opacity=opacity
}