// JavaScript Document
function getCookie(c_name)
{
if (document.cookie.length>0)
  {
  c_start=document.cookie.indexOf(c_name + "=")
  if (c_start!=-1)
    { 
    c_start=c_start + c_name.length+1 
    c_end=document.cookie.indexOf(";",c_start)
    if (c_end==-1) c_end=document.cookie.length
    return unescape(document.cookie.substring(c_start,c_end))
    } 
  }
return ""
}

function setCookie(c_name,value,expiredays)
{
var exdate=new Date()
exdate.setDate(exdate.getDate()+expiredays)
document.cookie=c_name+ "=" +escape(value)+
((expiredays==null) ? "" : ";expires="+exdate.toGMTString())
}

function checkCookie()
{
season=getCookie('season') 
//alert('Before: '+season)
if ((season==null) || (season=='')){
  var today=new Date()
  var month=today.getMonth()
  var date=today.getDate()
  var north = true;
  if (date > 20)
    month++;
  var season_num=Math.floor((month+(north?6:0))/3)%4
  //alert('After: '+season_num)
  if (season_num==0)
    setCookie('season','summer',365)
  else if (season_num==1)
    setCookie('season','fall',365)
  else if (season_num==2)
    setCookie('season','winter',365)
  else if (season_num==3)
    setCookie('season','spring',365)
}
season=getCookie('season') 
chooseStyle(season,60)
}

function setStylesheet(title, randomize){ //Main stylesheet switcher function. Second parameter if defined causes a random alternate stylesheet (including none) to be enabled
var i, cacheobj, altsheets=[""]
for(i=0; (cacheobj=document.getElementsByTagName("link")[i]); i++) {
if(cacheobj.getAttribute("rel").toLowerCase()=="alternate stylesheet" && cacheobj.getAttribute("title")) { //if this is an alternate stylesheet with title
cacheobj.disabled = true
altsheets.push(cacheobj) //store reference to alt stylesheets inside array
if(cacheobj.getAttribute("title") == title) //enable alternate stylesheet with title that matches parameter
cacheobj.disabled = false //enable chosen style sheet
}
}
if (typeof randomize!="undefined"){ //if second paramter is defined, randomly enable an alt style sheet (includes non)
var randomnumber=Math.floor(Math.random()*altsheets.length)
altsheets[randomnumber].disabled=false
}
return (typeof randomize!="undefined" && altsheets[randomnumber]!="")? altsheets[randomnumber].getAttribute("title") : "" //if in "random" mode, return "title" of randomly enabled alt stylesheet
}

function chooseStyle(styletitle, days){ //Interface function to switch style sheets plus save "title" attr of selected stylesheet to cookie
if (document.getElementById){
setStylesheet(styletitle)
//setCookie("mysheet", styletitle, days)
}
}