js"发送验证码"倒计时效果！

<input type="button" id="fsyzm" onclick="timedCount()"  class="btn5" value="发送校验码" />
<script type="text/javascript">
    var Time=3,    t;
    var c=Time
    function timedCount(){
        document.getElementById('fsyzm').value="请稍等(" + c + ")";
        document.getElementById('fsyzm').disabled="disabled";
        c=c-1;
        t=setTimeout("timedCount()",1000)
        if(c<0){
            c=Time;
            stopCount();
            document.getElementById('fsyzm').value="发送校验码";
            document.getElementById('fsyzm').removeAttribute("disabled");
        }
    }
    function stopCount(){
        clearTimeout(t);
    }
</script>