function setActiveStyleSheet(colour, layout, fontstyle) {
  var i, a, main;
  for(i=0; (a = document.getElementsByTagName("link")[i]); i++) {
    if(a.getAttribute("rel").indexOf("style") != -1 
       && a.getAttribute("title")
       ) {
      a.disabled = true;
      if(a.getAttribute("title") == (colour)) a.disabled = false;
      if(a.getAttribute("title") == (layout)) a.disabled = false;
      if(a.getAttribute("title") == (fontstyle)) a.disabled = false;
    }
  }
}
function getActiveStyleSheet(styletype) {
  var i, a;
  for(i=0; (a = document.getElementsByTagName("link")[i]); i++) {
    if(a.getAttribute("rel").indexOf("style") != -1 
       && a.getAttribute("title") 
       && a.getAttribute("title").indexOf(styletype) != -1
       && !a.disabled
       ) return a.getAttribute("title");
  }
  return null;
}
function getPreferredStyleSheet(styletype) {
  var i, a;
  for(i=0; (a = document.getElementsByTagName("link")[i]); i++) {
    if(a.getAttribute("rel").indexOf("style") != -1
       && a.getAttribute("rel").indexOf("alt") == -1
       && a.getAttribute("title")
       && a.getAttribute("title").indexOf(styletype) != -1
       ) {
       return a.getAttribute("title");}
  }
  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 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;
}
window.onload = function(e) {
  var colourCookie = readCookie("colour");
  var colour = colourCookie ? colourCookie : getPreferredStyleSheet("colour");
  var layoutCookie = readCookie("layout");
  var layout = layoutCookie ? layoutCookie : getPreferredStyleSheet("layout");
  var fontCookie = readCookie("font");
  var fontstyle = fontCookie ? fontCookie : getPreferredStyleSheet("font");
  setActiveStyleSheet(colour, layout, fontstyle);
}
window.onunload = function(e) {
  var colour = getActiveStyleSheet("colour");
  createCookie("colour", colour, 365);
  var layout = getActiveStyleSheet("layout");
  createCookie("layout", layout, 365);
  var fontstyle = getActiveStyleSheet("font");
  createCookie("font", fontstyle, 365);
}
var colourCookie = readCookie("colour");
var colour = colourCookie ? colourCookie : getPreferredStyleSheet("colour");
var layoutCookie = readCookie("layout");
var layout = layoutCookie ? layoutCookie : getPreferredStyleSheet("layout");
var fontCookie = readCookie("font");
var fontstyle = fontCookie ? fontCookie : getPreferredStyleSheet("font");
setActiveStyleSheet(colour, layout, fontstyle);