[ruslan_mart]

<div id="time" style="display:none">Осталось времени: <span></span></div>

var init, inis;
document.onmousemove = onInit;
document.onkeydown = onInit;
 
function onInit()
{
    var a = document.getElementById('time'), b = 5, c = a.getElementsByTagName('span')[0]
    a.style.display = 'none';
    if(init)
    {
        clearTimeout(init);
        if(inis) clearInterval(inis);
        init = 0;
        inis = 0;
    }
    init = setTimeout(function()
    {
        a.style.display = '';
        inis = setInterval(function()
        {
            c.innerHTML = b;
            b--;
            if(b < 0) document.location = 'test.php';
        }, 1000);
    }, 5000);
}