var selected = '';

function select(id) {
    document.getElementById(id).className += " selected";
}

function selectTab(id) {
    if(selected != '') {
        document.getElementById(selected).className = '';
        var old = selected.concat("-info");
        document.getElementById(old).className += " invisible";
    }
    selected = id;
    document.getElementById(id).className += " selected";
    var sNew = selected.concat("-info");
    document.getElementById(sNew).className =
            document.getElementById(sNew).className.replace( /(?:^|\s)invisible(?!\S)/ , '' );
}