function fold(id, url)
{
    var obj = document.getElementById(id);
    var obj_c = document.getElementById(id + '_c');

    if (obj) {
        var iHTML = obj_c.innerHTML;
        var e_title = iHTML.substr(5, iHTML.length - 5);
        if (obj.style.display == 'block') {
            obj.style.display = 'none';
            obj_c.innerHTML = '+';
        }
        else {
            obj.style.display = 'block';
            obj_c.innerHTML = '-';
        }
    }
    else {
        location.href = url;
    }
}