$(document).ready(function(){
	var posY = 0;		
	$("#menu a, #footer_menu a").click(function(){
		$('html,body').animate({scrollTop: $("#"+$(this).attr("title")).offset().top-70},'slow');	
	});
	
	$("#btn_top").click(function(){
		$('html,body').animate({scrollTop:0},'slow');		
	});
	
	$(window).scroll(function(){trouverPositionY();});
	
	function trouverPositionY(){
		if (typeof(window.pageYOffset) == 'number')
			posY = window.pageYOffset; //Netscape compliant
		else if(document.body && (document.body.scrollTop))
			posY = document.body.scrollTop;//DOM compliant
		else if(document.documentElement && (document.documentElement.scrollTop))
			posY = document.documentElement.scrollTop;//IE6 standards compliant mode
		if(posY < 70)
			$("#btn_top").fadeOut('slow');			
		else
			$("#btn_top").fadeIn('slow');			
	}
});