var ID;
var ticker;
var CurrentID;

function startTimer(id) {
    ID = id;
    ticker = setTimeout(tick, 250);
}

function tick() {
    document.getElementById(ID).style.display = "none";
    document.getElementById(CurrentID).style.display = "block";
}

function clearTick() {
    clearTimeout(ticker);
}

function setVisible(id) {
    document.getElementById(id).style.display = "block";
    if (id != CurrentID)
        document.getElementById(CurrentID).style.display = "none";
}

function hideNow() {
    if (ID != null) {
        document.getElementById(ID).style.display = "none";
    }
}