js例题（四）

<script type="text/javascript">
        window.setTimeout("Tiao()",1000)
        function Tiao()
        {
            var s =document.getElementById("shu")
            var n =document.getElementById("anniu")
            if(parseInt(s.innerHTML)<=0)
            {
                n.removeAttribute("disabled")
            }
            else
            {
                var x =parseInt(s.innerHTML)-1
                s.innerHTML = x
                window.setTimeout("Tiao()",1000)
            }
        }
            
        
        
        </script>