function setLang(baseurl,lang) {
    var url;
    var baseurlenght;
    var urlenght;
    var newurl;
    var urlpart1;
    url = document.location.href;
    if(url.match('/pl') || url.match('/en')){
        if(lang == 'pl'){
            window.location = url.replace("/en/", "/pl/");
        }else{
            window.location = url.replace("/pl/", "/en/");
        }
    }else{
        baseurlenght= baseurl.length;
        urlenght= url.length;
        url = url.substr(baseurlenght,urlenght);
        newurl = baseurl+lang+'/'+url;
        window. location = newurl;
    }
}