function PreloadImages() {
  if(PreloadImages.arguments.length > 0) {
    for(var i=0; i<PreloadImages.arguments.length; i++) {
      var image = new Image();
      image.src = PreloadImages.arguments[i];
    }
  }
}

function ToggleButton(btnName) {
  var btn = document.getElementById(btnName);
  if(btn) {
    btn.src = "media/" + btnName + ((btn.src.indexOf("_off")>=0)?"_on":"_off") + ((btn.src.indexOf(".jpg")>=0)?".jpg":".gif");
  }
}

function DisplayYear() {
  document.write((new Date()).getFullYear());
}

PreloadImages(
  "media/nav_btn_history_on.gif",
  "media/nav_btn_candf_on.gif",
  "media/nav_btn_automa_on.gif",
  "media/nav_btn_quality_on.gif",
  "media/nav_btn_sustain_on.gif",
  "media/nav_btn_location_on.gif",
  "media/nav_btn_home_on.gif"
);

function Querystring(qs) { // optionally pass a querystring to parse
  this.params = new Object()
  this.Get=GetQuerystring
	
  if(qs==null) qs = location.search.substring(1,location.search.length);
  if(qs.length==0) return;

  // Turn <plus> back to <space>
  // See: http://www.w3.org/TR/REC-html40/interact/forms.html#h-17.13.4.1
  qs = qs.replace(/\+/g, ' ');
  var args = qs.split('&'); // parse out name/value pairs separated via &
	
  // split out each name=value pair
	for(var i=0;i<args.length;i++) {
		var value;
		var pair = args[i].split('=');
		var name = unescape(pair[0]);

		if(pair.length == 2) value = unescape(pair[1]);
		else value = name;
		
		this.params[name] = value;
	}

  function GetQuerystring(key, default_) {
  	// This silly looking line changes UNDEFINED to NULL
  	if(default_==null) default_ = null;
  	
  	var value = this.params[key];
  	if(value==null) value = default_;
  	
  	return value;
  }
}