var layerRef="null", styleSwitch="null";
 var isNS = (navigator.appName == "Netscape");
layerRef = (isNS) ? "document" : "document.all";
styleSwitch = (isNS) ? "" : ".style";

browserVer=parseInt(navigator.appVersion);
if(browserVer >= 3)
        version="3";
      else
      version="2";
currentimg="1";	  
	  
if (version=="3") {
img_1=new Image();
img_1.src="images/alight_1.jpg";
img_2=new Image();
img_2.src="images/alight_2.jpg";
eval('ig_off=new Image(164, 13);');
eval('ig_off.src="../images/ig_off.gif"');
eval('ig_on=new Image(164, 13);');
eval('ig_on.src="../images/ig_on.gif"');
} 

function change()
{
commanda=layerRef+'["description'+currentimg+'"]'+styleSwitch+'.visibility="hidden"'
eval(commanda);
if (currentimg=="1")
{currentimg="2";} else {currentimg="1";}
if (version=="3")
{document['img_'].src=eval("img_" + currentimg + ".src");}
commanda=layerRef+'["description'+currentimg+'"]'+styleSwitch+'.visibility="visible"'
eval(commanda);
}


function grlist()
{
change();
MyTimer=setTimeout('grlist()', 4000);
return MyTimer;
}

function igOn()
{
if (version=="3") {
eval("document['ig_'].src=ig_on.src");
}
}

function igOff()
{
if (version=="3") {
eval("document['ig_'].src=ig_off.src");
}
}