<!-- Browser detection --> 
var isNetscape4 = document.layers;
var isNetscape6 = document.getElementById && !document.all
var DHTML = document.getElementById || document.all || document.layers;
var ordonnee = 200;

function getStyle(nom) {
	if (isNetscape6)
		style = document.getElementById(nom).style;
	else if (isNetscape4)
		style = document.layers[nom];
	else
		style = document.all[nom].style;
	return(style);
}
<!-- end of browser detection -->
<!-- Zoom Code -->
function visibilite(flag) {
if (!DHTML)
	return;
getStyle('loupe').visibility= (flag) ? 'hidden' : 'visible'
}
function visibilite2(flag) {
if (!DHTML)
	return;
getStyle('loupe2').visibility= (flag) ? 'hidden' : 'visible'
}