// Base = use only main.css
// Large font size = use main.css and font_large.css
// Extra large font size = use main.css and font_xlarge.css

function fontsizeup() {
  active = getActiveStyleSheet();
  switch (active) {
    case 'Base' : 
	  document.cookie = "font_cookie=Large font size";
      setActiveStyleSheet('Large font size');
      break;
    case 'Large font size' : 
      document.cookie = "font_cookie=Extra large font size";
      setActiveStyleSheet('Extra large font size');
      break;
    case 'Extra large font size':
      document.cookie = "font_cookie=Extra large font size";
	  break;  
    default :
      document.cookie = "font_cookie=Base";
      setActiveStyleSheet('Base');
      break;
  }
}

function fontsizedown() {
  active = getActiveStyleSheet();
  
  switch (active) {
    case 'Extra large font size' : 
	  document.cookie = "font_cookie=Large font size";
      setActiveStyleSheet('Large font size');
      break;
    case 'Large font size' : 
      document.cookie = "font_cookie=Base";
      setActiveStyleSheet('Base');
      break;
    case 'Base':
      document.cookie = "font_cookie=Base";
      break;
    default :
      document.cookie = "font_cookie=Base";
      setActiveStyleSheet('Base');
      break;
  }
}

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

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 'Base';
}

function getPreferredStyleSheet() {
  return ('Base');
}