<div class="area">         <p>             还可以输入<b class="num">140</b>字</p>         <textarea class="chackTextarea"></textarea>     </div>   <script type="text/javascript">     var txtobj = {         divName: "area", //外层容器的class         textareaName: "chackTextarea", //textarea的class         numName: "num", //数字的class         num: 140 //数字的最大数目     }     var textareaFn = function () {         //定义变量         var $onthis; //指向当前         var $divname = txtobj.divName; //外层容器的class         var $textareaName = txtobj.textareaName; //textarea的class         var $numName = txtobj.numName; //数字的class         var $num = txtobj.num; //数字的最大数目         function isChinese(str) {  //判断是不是中文             var reCh = /[u00-uff]/;             return !reCh.test(str);         }         function numChange() {             var strlen = 0; //初始定义长度为0             var txtval = $.trim($onthis.val());             for (var i = 0; i < txtval.length; i++) {                 if (isChinese(txtval.charAt(i)) == true) {                     strlen = strlen + 2; //中文为2个字符                 } else {                     strlen = strlen + 1; //英文一个字符                 }             }             strlen = Math.ceil(strlen / 2); //中英文相加除2取整数             if ($num - strlen < 0) {                 $par.html("超出 <b style='color:red;font-weight:lighter' class=" + $numName + ">" + Math.abs($num - strlen) + "</b> 字"); //超出的样式             }             else {                 $par.html("还可以输入 <b class=" + $numName + ">" + ($num - strlen) + "</b> 字"); //正常时候             }             $b.html($num - strlen);         }         $("." + $textareaName).live("focus", function () {             $b = $(this).parents("." + $divname).find("." + $numName); //获取当前的数字             $par = $b.parent();             $onthis = $(this); //获取当前的textarea             var setNum = setInterval(numChange, 500);         });     }     textareaFn(); </script>