function gotopage(addrs) {
  document.location.href=addrs;
}

function lng(lang) {
  var burl=document.location.href.split('/');
  var count=burl.length;
  burl[count-2]=lang;
  if (burl[count-1]=='') burl[count-1]='welcome.html';
  document.location.href=burl.join('/');
}