//		Fonctions pour la manipulation d'une couche défilante
		function getObj(nom)
				{
					if(document.getElementById)
						{
							this.obj = document.getElementById(nom);
							this.style = document.getElementById(nom).style;
						}
					else 
						if(document.all)
							{
								this.obj = document.all[nom];
								this.style = document.all[nom].style;
							}
						else
							if(document.layers)
								{
									this.obj = document.layers[nom];
									this.style = document.layers[nom].style;
								}
				}
			//		Appel var x = getObj('nom_de_la_couche');
			
			var clipTop, 
			clipWidth = 363, 
			clipHeight = 363, 
			clipBottom, topper = 0, /*		La position du point le plus haut de l'image*/
			lyrheight,  
			ecart = 25; /*Ecart par rapport à la position 0 du conteneur*/
			var time,amount,theTime,theHeight,DHTML;
			
			//		Initialisation des positions de la couche et les éléments additionnels
			
			function init_pos(conteneur)
				{
					DHTML = (document.getElementById || document.all || document.layers)
					if (!DHTML) return;
					//		Déclaration des différents éléments
					if(document.getElementById)
						{
							var cont = document.getElementById(conteneur);
							
							var la_couche = document.getElementById('couche');
							var la_bordure = document.getElementById('bordure');
							var le_up = document.getElementById('up');
							var le_down = document.getElementById('down');
							var l_orientation = document.getElementById('orientation');
							var l_echelle = document.getElementById('echelle');
							var comment = document.getElementById('comment_map');
						}
					else 
						if(document.all)
							{
								var cont = document.all[conteneur];
								
								var la_couche = document.all['couche'];
								var la_bordure = document.all['bordure'];
								var le_up = document.all['up'];
								var le_down = document.all['down'];
								var l_orientation = document.all['orientation'];
								var l_echelle = document.all['echelle'];
								var comment = document.all['comment_map'];
							}
						else
							if(document.layers)
								{
									var cont = document.layers[conteneur];
									
									var la_couche = document.layers['couche'];
									var la_bordure = document.layers['bordure'];
									var le_up = document.layers['up'];
									var le_down = document.layers['down'];
									var l_orientation = document.layers['orientation'];
									var l_echelle = document.layers['echelle'];
									var comment = document.layers['comment_map'];
								}
					if(!cont) return;
					//		Les dimensions et les positions du conteneur
					
					//		Petits calculs utiles pour IE
					var gauche = 0, haut = 0;
					var les_parents = cont;
					if(les_parents.offsetParent)
						{
							gauche = les_parents.offsetLeft;
							haut = les_parents.offsetTop;
							while(les_parents = les_parents.offsetParent)
								{
									gauche += les_parents.offsetLeft;
									haut += les_parents.offsetTop;
								}
						}
						
					largeur = cont.offsetWidth;
					hauteur = cont.offsetHeight;
					
					//		Les positions des éléments
					la_couche.style.top = 0;
					la_bordure.style.top = haut+ecart;
					clipTop = haut+ecart;
					clipBottom = clipTop+clipHeight;
					
					la_couche.style.left = gauche+(largeur-la_couche.offsetWidth)/2;
					la_bordure.style.left = gauche+(largeur-la_couche.offsetWidth)/2;	

					le_up.style.top = la_bordure.offsetTop;
					le_down.style.top = la_bordure.offsetTop+la_bordure.offsetHeight-le_up.offsetHeight;
					l_orientation.style.top =  la_bordure.offsetTop+1;
					l_echelle.style.top =  la_bordure.offsetTop+la_bordure.offsetHeight-l_echelle.offsetHeight-1;
					comment.style.top = la_bordure.offsetTop+la_bordure.offsetHeight+30;
					
					le_up.style.left = la_bordure.offsetLeft+(la_bordure.offsetWidth-le_up.offsetWidth)/2; 
					le_down.style.left = la_bordure.offsetLeft+(la_bordure.offsetWidth-le_down.offsetWidth)/2; 
					l_orientation.style.left =  la_bordure.offsetLeft+la_bordure.offsetWidth-l_orientation.offsetWidth-1;
					l_echelle.style.left =  la_bordure.offsetLeft+1;
					comment.style.left = gauche+(largeur-comment.offsetWidth)/2;
					
					var x = new getObj('couche');
					if (document.layers)
						{
							lyrheight = x.style.clip.bottom;
							x.style.clip.top = clipTop;
							x.style.clip.left = 0;
							x.style.clip.right = clipWidth;
							x.style.clip.bottom = clipBottom;
						}
					else 
						if (document.getElementById || document.all)
							{
								lyrheight = x.obj.offsetHeight;
								x.style.clip = 'rect('+clipTop+'px,'+clipWidth+'px,'+clipBottom+'px,1)';
							}
				}

			//		Défiler la couche
			function scrollayer(layername,amt,tim)
				//		amt: pixel de défilement, tim: temps d'attente avant un nouveau défilement
				{
					if (!DHTML) return;
					thelayer = new getObj(layername);
					if (!thelayer) return;
					amount = amt;
					theTime = tim;
					realscroll();
				}

			function realscroll()
				//		Le vrai scrolling
				{
					if (!DHTML) return;
					clipTop += amount;//		On ajoute de amt
					clipBottom += amount;
					topper -= amount;
					if (clipTop < 0 || clipBottom > lyrheight)
						{
							clipTop -= amount;
							clipBottom -= amount;
							topper += amount;
							return;
						}
					if (document.getElementById || document.all)
						{
							clipstring = 'rect('+clipTop+'px,'+clipWidth+'px,'+clipBottom+'px,0)';
							thelayer.style.clip = clipstring;
							thelayer.style.top = topper + 'px';
						}
					else
						if (document.layers)
							{
								thelayer.style.clip.top = clipTop;
								thelayer.style.clip.bottom = clipBottom;
								thelayer.style.top = topper;
							}
					time = setTimeout('realscroll()',theTime);
				}

			function stopScroll()
				{
					if (time) clearTimeout(time);
				}