function changeLanguage(tolang) {
    var loc = document.location.href;
    if ( loc.lastIndexOf("/eng/") != -1 ){
        tloc =  loc.replace("/eng/", "/"+tolang+"/");
    }

    if ( loc.lastIndexOf("/tc/") != -1 ){
        tloc =  loc.replace("/tc/", "/"+tolang+"/");
    }

    if ( loc.lastIndexOf("/gb/") != -1 ){
        tloc =  loc.replace("/gb/", "/"+tolang+"/");
    }

    window.location = tloc;
}