window.addEvent('domready', function() {
var fx = new Fx.Styles('LeFlux', {duration:2000, wait:false, transition: Fx.Transitions.Circ.easeOut});
 	
	var repereScroll= 0;
  
	$('btnHaut').addEvent('mouseover', function(){
							
		if(repereScroll!=0){	
		fx.start({
			'margin-top': repereScroll+100
		});
		repereScroll= repereScroll+100;
		}
	});
 
	$('btnBas').addEvent('mouseover', function(){
		if(repereScroll>= -400){
		fx.start({
			'margin-top': repereScroll-100
		});
		repereScroll= repereScroll-100;
		}
	});

									 });