function setActiveStyleSheetSize(size) {
	var title = readCookie("title");
	var colour = splitTitle(title)[1];
	if (colour) {
		title = size + " (" + colour + ")";
	} else {
		title = size;
	}
	createCookie("title",title,365);
	init(null);
}

function setActiveStyleSheetHiContrast(contrast) {
	var title = readCookie("title");
	var size = splitTitle(title)[0];
	if (contrast) {
		title = size + " (hi contrast)";
	} else {
		title = size;
	}
	createCookie("title",title,365);
	init(null);
}

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;
      }
    }
  }
}

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 = "";
  var txt = name+"="+value+expires+"; path=/";
  document.cookie = txt;
}

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 "standard text size";
}

function init(e) {
  var title = readCookie("title");
  var size = splitTitle(title)[0];
  var colour = splitTitle(title)[1];
  if (size) {
	title = size;
	if (colour) {
		title = title + " (" + colour + ")";
	}
  } else {
	title = getPreferredStyleSheet();
  }
  setActiveStyleSheet(title);
}

function splitTitle(title) {
  var size = '';
  var colour = '';
  var idx = title.indexOf('(');
  if (idx >= 0) {
	size = title.slice(0,idx-1);
        var pos = title.indexOf(')');
	colour = title.slice(idx+1,pos);
  } else {
	size = title;
	colour = "";
  }
  return [size,colour];
}

window.onload = init;

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

init(null);