body {margin-top:0}

a{
	text-decoration:none;
	}
body {
  text-align:center;
  }

 

#imagen
	{
	
	background-image: url(../imagenes/imagen.jpg);
	background-repeat: no-repeat;
	background-position: middle;
	width:1024px;
	height:685px;
	 margin-top:auto;/*lo que quieras poner de margin arriba*/
  margin-right:auto;
  margin-bottom:auto;
  margin-left:auto;
		}
.titulo
	{
		text-align:center;
		font-family: helvetica;
		font-size:29px;
		color: #ffffff;
		
		}