function show_layer(info,etat)
{
	var object = info;

	if (document.getElementById) 
	{
		if(document.getElementById(object)) document.getElementById(object).style.display = etat;
	} 
	else if (document.layers && document.layers[object])
	{ 
		if(document.layers[object]) document.layers[object].display = etat;
	} 
	else if (document.all)
	{ 
		if(document.all[object]) document.all[object].style.display = etat;
	}
}
		
function change_image (id,page) {
	// menu
	var obj = document.getElementById(id).src;	
	if (obj.lastIndexOf('-on')==-1 && id != page) {	
		var newobj = obj.substring(0,obj.lastIndexOf('.gif')) + "-on.gif";
		document.getElementById(id).src = newobj;
	}
	
	// sous menu
	if (document.getElementById(id+"-items")!=null) {	
		show_layer(id+"-items", 'block');
	}
}

function restore_image (id,page) {
	// menu
	var obj = document.getElementById(id).src;
	var newobj = obj.substring(0,obj.lastIndexOf('-on'));
	if (newobj != "" && id != page) document.getElementById(id).src = newobj + ".gif";

	// sous menu
	if (document.getElementById(id+"-items")!=null) {
		show_layer(id+"-items", 'none');
	}
}