function toggleDisplayById(id, displayMode) {
    return toggleDisplay(document.getElementById(id), displayMode);
}
function toggleDisplay(el, displayMode) {
    if(el.style.display == 'none')
        el.style.display = displayMode || 'block';
    else
        el.style.display = 'none';
    return false;
}
function onFaultTypeSelect(select, internet, phone, iptv) {

    var internetEl = document.getElementById(internet);
    var phoneEl = document.getElementById(phone);
    var iptvEl = document.getElementById(iptv);

    switch(select.value.toLowerCase()) {
        case 'internet':
            internetEl.style.display = 'block';
            phoneEl.style.display = 'none';
            iptvEl.style.display = 'none';
            break;
        case 'phone':
            internetEl.style.display = 'none';
            phoneEl.style.display = 'block';
            iptvEl.style.display = 'none';
            break;
        case 'both':
            internetEl.style.display = 'block';
            phoneEl.style.display = 'block';
            iptvEl.style.display = 'none';
            break;
        case 'iptv':
            internetEl.style.display = 'none';
            phoneEl.style.display = 'none';
            iptvEl.style.display = 'block';
            break;
        default:
            internetEl.style.display = 'none';
            phoneEl.style.display = 'none';
            iptvEl.style.display = 'none';
            break;
    }
}