function newImage(arg) {
  	if (document.images) {
  		rslt = new Image();
  		rslt.src = arg;
  		return rslt;
  	}
  }

  function changeImages() {
  	if (document.images && (preloadFlag == true)) {
  		for (var i=0; i<changeImages.arguments.length; i+=2) {
  			document[changeImages.arguments[i]].src = changeImages.arguments[i+1];
  		}
  	}
  }

  var preloadFlag = false;
  function preloadImages() {
  	if (document.images) {
  		TrainTravelNav01_on = newImage("images/Rail-Road_Home_Primary_Left_01_on.gif");
  		TrainTravelNav02_on = newImage("images/Rail-Road_Home_Primary_Left_02_on.gif");
  		TrainTravelNav03_on = newImage("images/Rail-Road_Home_Primary_Left_03_on.gif");
  		TrainTravelNav04_on = newImage("images/Rail-Road_Home_Primary_Left_04_on.gif");
  		TrainTravelNav05_on = newImage("images/Rail-Road_Home_Primary_Left_05_on.gif");
  		preloadFlag = true;
  	}
  }