// *** Image lists ***
	var UpImg = new Array();
	var DnImg = new Array();

	// *** Initialize the images  
	var ImageDir = BaseDir + "images/";	
	if (document.images) {       // if image object is available
	  for (var i = 0; i < ImageNames.length; i++) {
		Name = ImageNames[i];
		MapName= MapNames[i];
		UpImg[Name] = new Image();
		DnImg[Name] = new Image();
		UpImg[Name].src = ImageDir + MapName+ "Up.gif";
		DnImg[Name].src = ImageDir + MapName+ "Dn.gif";
	  }
	}
	// *** Swap images to UP
	function ButtonUp(Name) {
	   if (document.images) {
	    document.images[Name].src = UpImg[Name].src
	   }
	}

	// *** Swap images to DN
	function ButtonDn(Name) {
	   if (document.images) {
	    document.images[Name].src = DnImg[Name].src
	   }
	}