// stolen from Tim Bray, who had previously:
//   stolen wholesale from Zeldman, Willison and others
//    with thanks

function setActiveStyleSheet(title) {
  var i, a, main;
  for (i=0; (a = document.getElementsByTagName("link")[i]); i++) {
    if (a.getAttribute("rel")
        && a.getAttribute("rel").indexOf("style") != -1
        && a.getAttribute("title")) {
      a.disabled = true;
      if (a.getAttribute("title") == title) {
        a.disabled = false;
      }
    }
  }
}

function getActiveStyleSheet() {
  var i, a;
  for (i=0; (a = document.getElementsByTagName("link")[i]); i++) {
    if (a.getAttribute("rel")
        && a.getAttribute("rel").indexOf("style") != -1
        && a.getAttribute("title")
        && !a.disabled) {
      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 cookie = readCookie("style");
  var title;
  if (cookie == 'large' || cookie == 'normal') { 
    title = cookie; 
  } else { 
    title = 'normal';
  }
  setActiveStyleSheet(title);
}

window.onunload = function(e) {
  var title = getActiveStyleSheet();
  createCookie("style", title, 365);
}