test the string contain chinese words

檢查中文字
  <form name="form1">
  <input id="text1" type="text" name="text1" value="123" size="10">
  <input type="button" name="btn1" value="click me" onClick="chkword()">
  </form>
  <script type="text/javascript">
 
  function chkword(){
     alert (ischinese(document.form1.text1.value));
  }
 
  function ischinese(s){
    var ret=true;
    for(var i=0;i<s.length;i++)
    ret=ret && (s.charCodeAt(i)>=10000);
    return ret;
  }
 
  </script>