function create_cookie(name, value, days)
{
	if (days)
	{
		var date = new Date();
		date.setTime(date.getTime()+(days*24*3600*1000));
		
		var expires ="; expires="+date.toGMTString();
	}
	else
		var expires = "";
	
	document.cookie += name+"="+value+expires+"; path=/";
}

function read_cookie(name)
{
	var nameEQ = name + "=";
	var ca = document.cookie.split(';');
	for (var i=0; i< ca.length; i++)
	{
		var c = ca[i];
		while (c.charAt(0) == ' ') c = c.substring(1, c.length);
		if (c.indexOf(nameEQ) == 0) return c.substring(nameEQ.length, c.length);
	}
	
	return null;
}

function erase_cookie(name)
{
	create_cookie(name, "", -1);
}