function muovi(target){
	var step = new Array('0px','-570px','-1140px','-1710px','-2280px');
	$('#contenuto').animate({ marginLeft: step[target] }, 500);
}

function tictac(){
	if(c==4){ c = 0; }
	else { c = c+1; }
	muovi(c);
	t = setTimeout('tictac()',7000);
}

$(document).ready(function(){

	c = 0;
	var init = setTimeout('tictac()',7000);
	
	$('#tras1_menu a').click(function(e){
		e.preventDefault();
		var clicked = $(this).attr('class');
		muovi(clicked);
		clearTimeout(t);
	});

});