function montre_contact() { 
    if (navigator.appName=='Microsoft Internet Explorer') 
    { 
           document.all.Layer_contact.style.visibility='visible'; 
                   
    } 
    else 
    { 
           document.getElementById('Layer_contact').style.visibility='visible';
     
    } 
                 ;} 

// ----------------------------- 

function cache_contact() { 
    if (navigator.appName=='Microsoft Internet Explorer') 
    { 
           document.all.Layer_contact.style.visibility='hidden'; 
                   
    } 
    else 
    { 
           document.getElementById('Layer_contact').style.visibility='hidden';
     
    } 
                 ;}