jquery判断输入文字个数的统计代码

1、js代码部分

<script type="text/javascript">
            $(function() {

function albumName() {
                           var text = $("#album_name").val();
                            var counter = text.length;
                           $("#numtj var").text(counter);
                           $(document).keyup(function() {
                                  var text = $("#album_name").val();
                                  var counter = text.length;
                                 $("#name_word").text(counter);
                           });
                    }
            });
  </script>

2、html部分

<input type="text" maxlength="30" class="int_txt" name="album_name" id="album_name">
    <span class="count_txt"><span id="name_word">0</span>/30</span>

3、贴张图看下效果