[Medic84]

Код:

<span id="counter"></span>

<SCRIPT LANGUAGE = "JavaScript">
	var secs
	var timerID = null
	var timerRunning = false
	var delay = 1000
	
	InitializeTimer()
	
	function InitializeTimer()
	{
		// Set the length of the timer, in seconds
		secs = 15
		StopTheClock()
		StartTheTimer()
	}
	
	function StopTheClock()
	{
		if(timerRunning)
			clearTimeout(timerID)
		timerRunning = false
	}
	
	function StartTheTimer()
	{
		if (secs==0)
		{
			StopTheClock()
			window.location.href = "http://сайт.ру"
		}
		else
		{
			document.getElementById("counter").innerHTML = "Через " + secs + " сек страничка откроется"
			secs = secs - 1
			timerRunning = true
			timerID = self.setTimeout("StartTheTimer()", delay)
		}
	}
</SCRIPT>

Работает в теле HTML страницы