function test() {
	var version = parseInt (navigator.appVersion);
	if (version < 4) return 0;
	else return 1;
}

//debut recherche layer
function findLayer (id) {
		if (document.layers) { // NS
			return document.layers [id];
		}
		else if (document.all) {   // MSIE
			return document.all [id];
		}		
		else {
			return document.getElementById (id);
		}
}


function hideLayer (id) {
	   if (test()) {
		var obj = findLayer (id);
		if (obj.style) obj = obj.style; // "correction" MSIE
		obj.visibility = "hidden";
		}
}
		

function showLayer (id) {
		if (test()) {
			var obj = findLayer (id);
			if (obj.style) obj = obj.style; // "correction" MSIE
			obj.visibility = "visible";
		}
}
				//fin recherche layer et affichage


// deplacement du layer
var timerhaut;
var timerbas;
var layer;
var bas;
var spd;
var pos_init;	
	
	
function defil(id,dir,speed,pos,bottom) {
	//alert("test1");
	 bas = bottom;
	//alert('test2');
	 layer = id;
	 spd = speed;
	 pos_init = pos;
	if (test())  {
	 	var obj = findLayer (id);
		if (obj.style) obj = obj.style; // "correction" MSIE
		// direction
		if (dir == "haut") {
			ypos = parseInt(obj.top);
			if(ypos < pos_init) {
				obj.top = ypos + spd;
				timerhaut = setTimeout ("defil(layer,'haut',spd, pos_init,bas)",1);
			}
		}
		else {
			ypos = parseInt(obj.top);
			if(ypos >= bas) {
				obj.top = ypos - spd;
				timerbas = setTimeout("defil(layer,'bas',spd,pos_init,bas)",1);
			}
		}
	}
}