var refresh = 20;
    var seconds = refresh;
  
    function webcamRefresh()
    {
		document.form.counter.value = -- seconds;
		if (seconds <= 0)
		{
			var now = new Date();
			
			document.getElementById("webcam1").src = "cam2.php" + "?" + now.getTime();
			seconds = refresh;
		}
		refreshTimer = setTimeout("webcamRefresh()", 1000);
    }