function toggle_checkbox(checkbox) {
    var el = checkbox.previousSibling;
    try {
        el.className = checkbox.checked ? "checked" : "";
    } catch (e) {;}
}     

function toggle_tip(element, state) {
    try {
        for(var i=0; i<element.parentNode.childNodes.length; i++) {
            var el = element.parentNode.childNodes[i];
            if(el.className == "tip")  el.style.display = state ? 'block' : 'none';
        }
    } catch (e) {;}
}

function set_logo_link() {
    try { 
        var logo = document.getElementById("logo_link");
        if(logo) logo.setAttribute('href', 'http://' + location.hostname + '/');
    } catch (e) {;}   
}