function swapth() {

var url=document.URL;

countstr=url.length;
data=url.substr(countstr-1);

if(data=='/'){
url=url+'index.html';
}

sp_url=url.split("."); 
pointtype=(sp_url.length)-1;

type=sp_url[pointtype];
newurl =url.replace('.'+type,'_th.'+type);
window.location=newurl;
//alert(newurl);

}
function swapen() {
		var url=document.URL;
			newurl =(url).replace('_th','');
			window.location=newurl;
}