var url;
var server;
var page;
var path;

var b2g_url="gb.hyd.gov.hk/TuniS";
var loc=document.location.href;
var protocal=loc.substring(0,loc.indexOf("://"));
var contextRoot;
var chs=false;
var cht=false;
var eng=false;
if (loc.indexOf(b2g_url)>=0)
{
	// current in chs
	chs=true;
	url=loc.substring(loc.indexOf(b2g_url)+b2g_url.length+1);
} 
else
{
	url=loc.substring(loc.indexOf("://")+3);
}
server=url.substring(0,url.indexOf("/"));
if (server==null)
	server="";
path=url.substring(url.indexOf("/"));
if (path==null)
	path="";
if (path.indexOf("/chi/")>0)
{
	contextRoot=path.substring(0,path.indexOf("/chi/"));
} else if (path.indexOf("/eng/")>0)
{
	contextRoot=path.substring(0,path.indexOf("/eng/"));
}
if (contextRoot==null)
	contextRoot="";
	 
page=path.substring(contextRoot.length+4);
if (page==null)
	page="";
//	alert("url="+url);
	
//	alert("server="+server);
	
//	alert("path="+path);
//	alert("page="+page);
//	alert("contextRoot="+ contextRoot);
function lang(val)
{


var redir_url;

	
	switch (val)
	{
		case "chs":
			redir_url=protocal+"://"+b2g_url+"/"+server+contextRoot+"/chi"+page;
			break;
		case "cht":
			redir_url=protocal+"://"+server+contextRoot+"/chi"+page;
			break;
		case "eng":
			redir_url=protocal+"://"+server+contextRoot+"/eng"+page;
			break;
		case "chi":
			if (chs)
				redir_url=protocal+"://"+server+contextRoot+"/chi"+page;
			else
				redir_url=protocal+"://"+b2g_url+"/"+server+contextRoot+"/chi"+page;
			break;

	}
	document.location.href=redir_url;
}
function lang_tag(chtText,chsText)
{
	if (chs)
		imgLang.alt=chtText;
	else
		imgLang.alt=chsText;;
	
}
function textVersion()
{
		if (chs)
			redir_url=protocal+"://"+b2g_url+"/"+server+contextRoot+"/textonly"+path;
		else
			redir_url=protocal+"://"+server+contextRoot+"/textonly"+path;

	document.location.href=redir_url;
//document.location.href=protocal+"://"+server+"/TextOnly" +path;
}
function graphicVersion()
{
		if (chs)
			redir_url=protocal+"://"+b2g_url+"/"+server+path.substring(9,path.length);
		else
			redir_url=protocal+"://"+server+path.substring(9,path.length);

	document.location.href=redir_url;	
//document.location.href=protocal+"://"+server+ path.substring(9,path.length);
}