var g_max_seconds = 0;

function showPuzzleFor(n_seconds)
{
    g_max_seconds = n_seconds;
    var elm = document.getElementById("puzzle");
    elm.style.visibility = "visible";
    setTimeout("hidePuzzle()", n_seconds * 1000);
}

function hidePuzzle()
{
    var elm = document.getElementById("puzzle");
    elm.innerHTML = "?"
    elm = document.getElementById("mainForm");
    elm.style.visibility = "visible";
    focusInput();
}