var ie4=document.all&&!document.getElementById;
var ns4=document.layers;
var DOM2=document.getElementById;
var opera=(navigator.userAgent.indexOf("Opera")!=-1)?true:false
var oldimageth = null;

if (document.layers) {
	visible = 'show';
	hidden = 'hide';
}
else
if (document.all) {
	visible = 'visible';
	hidden = 'hidden';
}


var isNav, isIE;
if (parseInt(navigator.appVersion) >= 4)
{ if (navigator.appName == "Netscape")
   { isNav = true }
   else
   { isIE = true }
}

function thumb1swap(imageth,newmain,caption,thisClass) 
{ 	
	if (!oldimageth) 
		oldimageth = document.images["firstthumb"];

	oldimageth.className = thisClass;

	document.images["mainimg"].src=newmain;
	document.images["mainimg"].alt=caption;
	imageth.className = thisClass + " IMAGEOPACITY";
	
	oldimageth = imageth;

	//if (DOM2) && document.getElementById("caption"){
	//	document.getElementById("caption").innerHTML = caption;
	//}
	//else if (ie4)
	//	document.all.help.innerHTML = caption;
	//else if (ns4){
	//	document.layers.caption.document.write(caption);
	//	document.layers.caption.document.close();
	//}	
}