// JavaScript document

function setActiveStyleSheet(title) {
  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") == title) a.disabled = false;
    }
  }
  highlightSize(title);
  display();
  setHeight();
}

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

function getPreferredStyleSheet() {
  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")
       ) 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;
}

// if javascript is enabled, show text sizer
function display() {
	document.getElementById("textSize").className = "visible";
}

// highlight the selected text size option
function highlightSize(title) {
	var textSizeOptions = document.getElementById("textSizeOptions");
	for(n = 0; n < textSizeOptions.childNodes.length; n++) {
		currentOption = textSizeOptions.childNodes[n];
		selectedOption = "nav_" + title;
		if (currentOption.nodeName=="LI") {
			if (currentOption.id == selectedOption) {
				currentOption.className = "selected";
				currentOption.childNodes[0].className = "selected";
			} else {
				currentOption.className = "";
				currentOption.childNodes[0].className = "";				
			}
		}
	}
}

// initialize the styleswitcher
function initStyleSwitcher() {
  var cookie = readCookie("style");
  var title = cookie ? cookie : getPreferredStyleSheet();
  setActiveStyleSheet(title);
}

addLoadEvent(initStyleSwitcher);

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