// Example:
// alert( readCookie("myCookie") );
function readCookie(name)
{
  var cookieValue = "";
  var search = name + "=";
  if(document.cookie.length > 0)
  { 
    offset = document.cookie.indexOf(search);
    if (offset != -1)
    { 
      offset += search.length;
      end = document.cookie.indexOf(";", offset);
      if (end == -1) end = document.cookie.length;
      cookieValue = unescape(document.cookie.substring(offset, end))
    }
  }
  return cookieValue;
}

// Example:
// writeCookie("myCookie", "my name", 24);
// Stores the string "my name" in the cookie "myCookie" which expires after 24 hours.
function writeCookie(name, value)
{
  document.cookie = name + "=" + escape(value);
}


function mostrarIntro()
{
	var cookieValor = readCookie("intro");
	//if (cookieValor == "" || cookieValor == "no" )
	if (cookieValor == "no" )
	{
		return;
	}
	writeCookie("intro", "no");
	var ancho = document.documentElement.clientWidth
	var coordX = Math.ceil(ancho / 2 - 1024 / 2)-10;
	var obj = document.getElementById("banner_principal");
	obj.style.visibility = "hidden";
	var obj = document.getElementById("banner_vidriera");
	obj.style.visibility = "hidden";
	obj = document.getElementById("intro");
	obj.style.left = coordX + "px";
	obj.style.display = "block";
}

function cerrarIntro()
{
	var obj = document.getElementById("banner_principal");
	obj.style.visibility = "visible";
	var obj = document.getElementById("banner_vidriera");
	obj.style.visibility = "visible";
	obj = document.getElementById("intro");
	obj.style.display = "none";
}