var undefined; 
function UserAgent(){
	var b=navigator.appName.toUpperCase();

	if(b=="NETSCAPE")this.b="ns";
	else if(b=="MICROSOFT INTERNET EXPLORER")this.b="ie";
	else if(b=="OPERA")this.b="op";
	else this.b=b;

	this.version=navigator.appVersion;
	this.v=parseInt(this.version);

	this.ns=(this.b=="ns" && this.v>=4);
	this.ns4=(this.b=="ns" && this.v==4);
	this.ns5=(this.b=="ns" && this.v==5);

	this.ie=(this.b=="ie" && this.v>=4);
	this.ie4=(this.version.indexOf('MSIE 4')>0);
	this.ie5=(this.version.indexOf('MSIE 5')>0);
	this.ie55=(this.version.indexOf('MSIE 5.5')>0);
	this.ie6=(this.version.indexOf('MSIE 6')>0);

	this.op=(this.b=="op");
	this.op4=(this.b=="op" && this.v==4);
	this.op5=(this.b=="op" && this.v==5);
}

at=new UserAgent();

 
 
function exchanger(name){
	this.lyr=null;	this.isDynamic=false;
	this.name=name||"";
	this.fakeid=0;

	if(name==null || name==""){
		this.isDynamic=true;
		this.create();
	}else{
		this.name=name;
		if(at.ns4){
			this.lyr=window.document.layers[this.name];
		}
	}
}

exchanger.prototype.create=function(){
	if(at.ns4){
		this.lyr=new Layer(0);
		this.visibility="hide";
	}else if(at.ie || at.ns5){
		this.lyr=document.createElement("IFRAME");
		this.lyr.width=0;
		this.lyr.height=0;
		this.lyr.marginWidth=0;
		this.lyr.marginHeight=0;
		this.lyr.frameBorder=0;
		this.lyr.style.visibility="hidden";
		this.lyr.style.position="absolute";
		this.lyr.src="";
		this.name="tongIFrame"+window.frames.length;
		 
		this.lyr.setAttribute("id",this.name);
		 
		this.lyr.setAttribute("name",this.name);
		document.body.appendChild(this.lyr);
	}
}

exchanger.prototype._send=function(url){
	this.fakeid+=1;
	var newurl="";
	if(url.indexOf("?") >=0)
		newurl=url+"&fakeId"+this.fakeid;
	else
		newurl=url+"?fakeId"+this.fakeid;

	if(this.isDynamic||at.ns4)
		this.lyr.src=newurl;
	else{
		if(at.ie || at.ns5 || at.op){
			window.frames[this.name].document.location.replace(newurl);
		}
	}
}

exchanger.prototype._clear=function(varName){
	if(at.ns4){
		return eval("this.lyr."+varName+"=undefined");
	}else if(at.ie || at.ns5 || at.op){
		var estr="window.frames['"+this.name+"']."+varName+"=undefined";
		return eval(estr);
	}
}

exchanger.prototype._recv=function(varName){
	if(at.ns4){
		return eval("this.lyr."+varName);
	}else if(at.ie || at.ns5 || at.op){
		var estr="window.frames['"+this.name+"']."+varName;
		return eval(estr);
	}
}

exchanger.prototype.send=function(url){
	this._clear("res");
	this._send(url);
}

exchanger.prototype.recv=function(){
	return this._recv("res");
}

exchanger.prototype.callback=function(fn,tm){
	xfer_rx(fn,tm);
}

var xfer = new exchanger("myframe");

function xfer_rx(fn,tm){
	var dt=xfer.recv();
	if(dt==undefined){
		setTimeout("xfer_rx('"+fn+"',"+tm+")",tm);
	}else{
		eval(fn);
	}
}

function rfr(id){
	xfer.send('/rfr.php?id='+id);
}