function na_preload_img()
	{ 
	  var img_list = na_preload_img.arguments;
	  if (document.preloadlist == null) 
	    document.preloadlist = new Array();
	  var top = document.preloadlist.length;
	  for (var i=0; i < img_list.length-1; i++) {
	    document.preloadlist[top+i] = new Image;
	    document.preloadlist[top+i].src = img_list[i+1];
	  } 
	}

	function na_change_img_src(id, nsdoc, rpath, preload)
	{ 
	  var img = eval((navigator.appName.indexOf('Netscape', 0) != -1) ? nsdoc+'.'+id : 'document.all.'+id);
	  if (id == '')
	    return;
	  if (img) {
	    img.altsrc = img.src;
	    img.src    = rpath;
	  } 
	}

	function na_restore_img_src(id, nsdoc)
	{
	  var img = eval((navigator.appName.indexOf('Netscape', 0) != -1) ? nsdoc+'.'+id : 'document.all.'+id);
	  if (id == '')
	    return;
	  if (img && img.altsrc) {
	    img.src    = img.altsrc;
	    img.altsrc = null;
	  } 
	}