function num_dias(num) {
var expdate = new Date();
	expdate.setTime(expdate.getTime() +  (24 * 60 * 60 * 1000 * num)); 
	return expdate;
}
function getCookieVal (offset) {
	var endstr = document.cookie.indexOf (";", offset);
	if (endstr == -1)
		endstr = document.cookie.length;
	return unescape(document.cookie.substring(offset, endstr));
}
function GetCookie (name) {
	var arg = name + "=";
	var alen = arg.length;
	var clen = document.cookie.length;
	var i = 0;
	while (i < clen) {
		var j = i + alen;
		if (document.cookie.substring(i, j) == arg)
			return getCookieVal (j);
		i = document.cookie.indexOf(" ", i) + 1;
		if (i == 0) break; 
	}
	return null;
}  
function SetCookie (name, value) {
	var argv = SetCookie.arguments;
	var argc = SetCookie.arguments.length;
	var expires = (argc > 2) ? argv[2] : null;
	var path = (argc > 3) ? argv[3] : null;
	var domain = (argc > 4) ? argv[4] : null;
	var secure = (argc > 5) ? argv[5] : false;
	document.cookie = name + "=" + escape (value) +
		((expires == null) ? "" : ("; expires=" + expires.toGMTString())) +
		((path == null) ? "" : ("; path=" + path)) +
		((domain == null) ? "" : ("; domain=" + domain)) +
		((secure == true) ? "; secure" : "");
}