function change_calque(elm) {
var div = elm.parentNode.getElementsByTagName('div')[0];
if (div.style.display=="none" ) {
div.style.display = "block";
elm.innerHTML = "Cacher";
} else {
 div.style.display = "none";
 elm.innerHTML = "Réponse";
 }
 }

 
 function deroule(elm2) {
var div = elm2.parentNode.getElementsByTagName('div')[0];
if (div.style.display=="none" ) {
div.style.display = "block";
elm2.innerHTML = "<img src='images/fleche-haut.png' alt='Fleche' /> ";
} else {
 div.style.display = "none";
 elm2.innerHTML = "<img src='images/fleche-bas.png' alt='Fleche' /> ";
 }
 }