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);
}

var THEME_KEY = "trainingtheme";	// this key is used to store the selected theme.
var THEMES_FOLDER_PATH = "css/";
var DEFAULT_THEME = "theme0";

function insertStyleSheet() {
	var s = readCookie(THEME_KEY);
	if (s == null) s = DEFAULT_THEME;
	document.writeln('<link href="'+THEMES_FOLDER_PATH+s+'/'+s+'.css" type="text/css" rel="stylesheet">');
}

function setTheme(name) {
	//DeleteCookie(THEME_KEY);					
	createCookie(THEME_KEY, name, 365);
	self.location = self.location;	// simple trick to reload the current document
}

insertStyleSheet();