<select class="input04" id="1" name="in_class1" onchange="setchange1(this)" style="width:100px;height:20px;">

                        <option selected="selected" value="0">  &lt; 请选择 &gt;  </option>

                        <option value="1">哈哈哈</option>

                    </select>

     function setchange1(v) {

           var cg=parseInt(v.id) + 1;

             $.post("../../tools/yiliaofuwu.ashx", { "action": "one","parenid":v.value }, function (data) {

                 var table = data.r;

                 // $("#" + cg).attr("disabled", "false");

                 $("#" + cg).removeAttr("disabled");

                $("#" + cg).empty();

                $("#" + cg).append("<option selected='selected'  value=0>请选择..</option>");

                for (var i = 0; i < table.length; i++) {

                    var item = table[i];

                    // var option = $("<option  value="+item.id+">"+item.name+"</option>");

                    $("#" + cg).append("<option  value=" + item.Id + ">" + item.Name + "</option>");

                }

                //返回的是json格式的数据

            }, "json");

        }