var nbrMargin = 170;

function haut(){
	if(nbrMargin >= -2){
	nbrMargin -= 7;	
	document.getElementById("tbgallery").style.marginTop = nbrMargin+"px";
	t = setTimeout("haut()",10);
	}
}

function bas(){
	if(nbrMargin != 170){
	nbrMargin += 7;	
	document.getElementById("tbgallery").style.marginTop = nbrMargin +"px";
	t = setTimeout("bas()",10);
	}
}

function fin(){
	clearTimeout(t);
}