如何使用JQuery在5秒后清除文本框值？

I have tried this :

我试过这个：

  <script type="text/javascript">
        $(function() {
            $("#button").click( function()
            {
                alert('button clicked'); // this is calling
                setTimeout(function(){
                    alert('setTimeout');  // this is not calling
                    document.getElementById('clearTxt').value = "";
                }, 9000);
            }
        );
        });
    </script>
  <script type="