下拉框联动

来源：互联网发布：xpath python 编辑：程序博客网时间：2024/05/16 01:09
<html>   <head><title>test select changed</title></head>   <script language='javascript'>     // 更新二级服务类型   function updateSubServer() {      var arrays = [['100', '合肥', '101'],['100', '阜阳','102'],['200', '南京', '201'], ['200', '苏州', '202']];      clear_sub_server();       var sub_servers2 = document.getElementById("sub_server");         var option_1 = null;      for (var i = 0; i < arrays.length; i++) {          option_1 = document.createElement("option");          if (document.forms[0].server.options[document.forms[0].server.selectedIndex].value == arrays[i][0]) {             option_1.text = arrays[i][1];              option_1.value = arrays[i][2];            sub_servers2.add(option_1);         }       }   }    // 清除二级服务类型，只留一个空的选择项   function clear_sub_server() {       var sub_servers = document.getElementById("sub_server");       while(sub_servers.childNodes.length > 0) {           sub_servers.removeChild(sub_servers.childNodes[0]);       }       var option_2 = document.createElement("option");       option_2.text = "---请选择---";       option_2.value = "";      sub_servers.add(option_2);   }     // 输入校验   function checkInput() {        if (document.forms[0].server.value == '') {           alert('请输入服务类型!');           return false;      }       if (document.forms[0].sub_server.value == '') {         alert('请输入二级服务类型!');         return false;      }      document.forms[0].submit();   }   </script>   <body>   <form name='form1' action='#' method='get' onsubmit="checkInput();return false;">      省份：<select name='server' id='server' onchange='updateSubServer();'>      <option value=''>---请选择---</option>      <option value='100'>安徽</option>      <option value='200'>江苏</option>   </select>   市：<select name='sub_server' id='sub_server'>   <option value=''>---请选择---</option>      </select>       <input type='submit' />   </form>   </body>   </html>