function mtSignIn() {
    var doc_url = document.URL;
    doc_url = doc_url.replace(/#.+/, '');
    var url = '<$mt:RemoteSignInLink$>';
    if (is_preview) {
        if ( document['comments_form'] ) {
            var entry_id = document['comments_form'].entry_id.value;
            url += '&entry_id=' + entry_id;
        } else {
            url += '&return_url=<$mt:BlogURL encode_url="1"$>';
        }
    } else {
        url += '&return_url=' + encodeURIComponent(doc_url);
    }
    mtClearUser();
    location.href = url;
}