ie4 = ((navigator.appName == "Microsoft Internet Explorer") && (parseInt(navigator.appVersion) >= 4 )) 
ns4 = ((navigator.appName == "Netscape") && (parseInt(navigator.appVersion) >= 4 )) 

if (ns4) { 
layerRef="document.layers"; 
styleRef=""; 
} else { 
layerRef="document.all"; 
styleRef=".style"; 
} 

function afficheCalque(calque) 
{ 
eval(layerRef + '["' + calque +'"]' + styleRef + '.visibility = "visible"'); 
} 

function cacheCalque(calque) 
{ 
eval(layerRef + '["' + calque +'"]' + styleRef + '.visibility = "hidden"'); 
} 

function affiche1() 
{ 
eval(layerRef + '["div1"]' + styleRef + '.visibility = "visible"'); 
} 

function cache1() 
{ 
eval(layerRef + '["div1"]' + styleRef + '.visibility = "hidden"'); 
}