function affiche_grande (id_photo,num) {
if (older_photo !="") {
document.getElementById('petite_photo'+older_photo).className ="image_entremont";
}
document.getElementById('grande_photo').src ="diaporama/photo"+id_photo+"_grd.jpg";
document.getElementById('petite_photo'+id_photo).className ="image_entremont_on";
document.getElementById('lenum_form').value =num;
older_photo = id_photo;
}

// Masque le layer //
function hideIt(layerName){	
document.getElementById(layerName).style.visibility ="hidden";
}
function showIt(layerName){ 
document.getElementById(layerName).style.visibility ="visible";
}

lance_diapo="";

function lancer_diaporama() {
document.getElementById('cont2').className ="contenu_diaporama";
document.getElementById('diaporama').style.visibility ="visible";
document.getElementById('id_cat').style.visibility ="hidden";
preload();
}

function fermer_diaporama() {
document.getElementById('cont2').className ="cont";
document.getElementById('diaporama').style.visibility ="hidden";
document.getElementById('id_cat').style.visibility ="visible";
stop_diapo() ;
document.getElementById('grd_diapo').src = 'img_com/vide.gif';
}

function diaporama (){
document.getElementById('fenetre_vignette').style.visibility ="hidden";
img_debut ();
la_vitesse = 4000 / document.num_diapo22.lenum_vitesse.value ;
eval ("lance_diapo = setInterval ('img_suivante ()',"+la_vitesse+");");
document.getElementById('img_loader').style.visibility ="visible";
}

function img_debut (){
stop_diapo();
the_num = 1 ;
num_img = tabjs [the_num];
open_gr_img (num_img,the_num);
}

function open_gr_img (num_img,the_num) {
// document.gr_photo.src = num_img;
document.getElementById('grd_diapo').src = 'diaporama/photo'+num_img+'_grd.jpg';
document.getElementById('texte_des_photo').innerHTML  = tabtexte [the_num];
document.num_diapo22.lenum_form22.value = the_num;
old_num = the_num;
}

function stop_diapo() {
if (lance_diapo){
clearTimeout(lance_diapo);
lance_diapo ="";
document.getElementById('img_loader').style.visibility ="hidden";
}
}

function img_suivante (){
the_num = document.num_diapo22.lenum_form22.value;
the_num =parseInt (the_num);
the_num = the_num +1 ;
num_img = tabjs [the_num];
if (the_num  < tabjs.length) { 
open_gr_img (num_img,the_num);
}else if (the_num  == tabjs.length && lance_diapo !=""){
stop_diapo();
}
}

function img_precedente (){
stop_diapo();
the_num = document.num_diapo22.lenum_form22.value;
the_num =parseInt (the_num);
the_num = the_num  - 1 ;
num_img = tabjs [the_num];
if (the_num  > 0) { 
open_gr_img (num_img,the_num);
}
}


function diminue_vitesse() {
if (document.num_diapo22.lenum_vitesse.value > 1) {
document.num_diapo22.lenum_vitesse.value = document.num_diapo22.lenum_vitesse.value - 1;
la_vitesse = 4000 / document.num_diapo22.lenum_vitesse.value ;
clearTimeout(lance_diapo);
lance_diapo = "";
eval ("lance_diapo = setInterval ('img_suivante ()',"+la_vitesse+");");
}
}

function augmente_vitesse() {
if (document.num_diapo22.lenum_vitesse.value < 5) {
document.num_diapo22.lenum_vitesse.value = parseInt (document.num_diapo22.lenum_vitesse.value) + 1;
la_vitesse = 4000 / document.num_diapo22.lenum_vitesse.value ;
clearTimeout(lance_diapo);
lance_diapo = "";
eval ("lance_diapo = setInterval ('img_suivante ()',"+la_vitesse+");");
}
}