pageHeight =  window.innerHeight;
pageHeight = (pageHeight)? pageHeight: document.documentElement.clientHeight;
pageHeight = (pageHeight)? pageHeight: document.body.clientHeight;
var position_x = 860/2+50;
var position_y = pageHeight/2-300 //(hauteur ecran - hauteur image)/2
var position_y_div = pageHeight/2-100 //(hauteur ecran - hauteur image)/2
function f_scrollTop() {
	return f_filterResults (
		window.pageYOffset ? window.pageYOffset : 0,
		document.documentElement ? document.documentElement.scrollTop : 0,
		document.body ? document.body.scrollTop : 0
	);
}
function f_filterResults(n_win, n_docel, n_body) {
	var n_result = n_win ? n_win : 0;
	if (n_docel && (!n_result || (n_result > n_docel)))
		n_result = n_docel;
	return n_body && (!n_result || (n_result > n_body)) ? n_body : n_result;
}

function ouvrir_menu(source_img,titre_img,taille_img)
{
odiv_wait = document.getElementById('div_wait');
show_div_wait();
test = 1;
cote = 20;
largeur = 640 + cote;
largeur_div = 139;
if (taille_img < 0) { largeur = 360 + cote;}
ab_zoom = document.getElementById("zoom");
ab_zoom.src = source_img;
ab_menu_context = document.getElementById("menu_context");
document.getElementById("zoom_title").innerHTML = titre_img;
ab_menu_context.style.top = position_y+f_scrollTop()+'px';
odiv_wait.style.top = position_y_div+f_scrollTop()+'px';
ab_menu_context.style.width = largeur+'px';
ab_menu_context.style.left = position_x-(largeur/2)+'px';
odiv_wait.style.left = position_x-(largeur_div/2)+'px';
img = new Image();
img.src = source_img;
waitForLoading();
}
function waitForLoading() {
if (!img.complete) {     
    setTimeout(waitForLoading, 30); return; }
else { if (test == 1) {ab_menu_context.style.visibility = "visible"; hide_div_wait();}}
}
function fermer_menu()
{
hide_div_wait();
ab_menu_context.style.visibility = "hidden";
ab_menu_context.style.width = 0+"px";
ab_zoom.src = "";
test = 0;
}

            <!-- Scroller de pointeur -->
var scroller_msg='Cliquer sur un nom de MODELE pour consulter la FICHE&nbsp;ARTICLE&nbsp;Détaillée...'
var dismissafter=0.5
var initialvisible=0
if (document.all)
document.write('<marquee id="curscroll" style="position:absolute;width:150px; height:17px; border:1px solid black;font-size:15px;background-color:white;visibility:hidden;z-index:501;">'+scroller_msg+'</marquee>')
function followcursor(){
if (initialvisible==0){
curscroll.style.visibility="visible"
initialvisible=1
}
curscroll.style.left=document.body.scrollLeft+event.clientX+10+'px';
curscroll.style.top=f_scrollTop()+event.clientY+10+'px';
}
function dismissmessage(){
curscroll.style.visibility="hidden"
}
if (document.all){
document.onmousemove=followcursor
document.ondblclick=dismissmessage
if (dismissafter!=0)
setTimeout("dismissmessage()",dismissafter*1000)
}

            <!-- ????????????????????????? -->
function displayImage(imageInitiale) {
	win = window.open("","Win","menubar=no");
	win.document.open("text/html");
	win.document.write('<STY' + 'LE><!--\n');
	win.document.write('body { margin-left: 0; margin-top: 0 }\n');
	win.document.write('--></STY' + 'LE>\n');
	win.document.write('<SCR' + 'IPT><!--\n');
	win.document.write('function resize() {\n');
	if (document.all)
		win.document.write('resizeTo(document.images[0].width+10,document.images[0].height+28);\n');
	else
		win.document.write('resizeTo(document.images[0].width+6,document.images[0].height+26);\n');
	win.document.write('} //--></SCR' + 'IPT>\n');
	win.document.write('<BO' + 'DY topmargin="0" leftmargin="0">');
	win.document.write('<IMG Src="' + imageInitiale.src + '" onLoad="resize()">');
	win.document.write('</BO' + 'DY>');
	win.document.close();
}
            <!-- Waiter -->
function show_div_wait(){
odiv_wait.style.visibility="visible";
}

function hide_div_wait(){
odiv_wait.style.visibility="hidden";
}