function setCookie (name, value, expires) {
  document.cookie = name + "=" + escape (value) +
  ((expires) ? "; expires=" + expires.toGMTString() : "");
}

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 createCookie(name,value,days) {
	if (days) {
		var date = new Date();
		date.setTime(date.getTime()+(days*24*60*60*1000));
		var expires = "; expires="+date.toGMTString();
	}
	else var expires = "";
	document.cookie = name+"="+value+expires+"; path=/";
}

function readCookie(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 eraseCookie(name) {
	createCookie(name,"",-1);
}