function decompte(){
seconde--;

if (seconde<0) {seconde=59;minute--;}
if (minute<0) {minute=59;heure--;}
if (heure<0) {heure=23;jour--;}
if (seconde<10) {b="0";} else {b="";}
if (minute<10) {a="0";} else {a="";}
if (heure<10) {c="0";} else {c="";}

var chrono=jour+" jour(s) "+c+heure+":"+a+minute+":"+b+seconde;
var taille=document.getElementById("chrono").firstChild.nodeValue.length;

document.getElementById("chrono").firstChild.replaceData(0,taille,chrono);

chrono=setTimeout("decompte()",1000);


}