ajax 遍历select 下拉框

html ：<select id="type"   > </select>

js代码：

<script type="text/javascript"> 
//动态绑定下拉框项 
        function addnotice() { 
            $.ajax({ 
                url: "${pageContext.request.contextPath}/dictionary/jindex.action?sign=4",      //后台返回json数据
                type: "post", 
                dataType: "json", 
                contentType: "application/json", 
                traditional: true, 
                success: function (data) { 
                    for (var i in data) { 
                        var jsonObj =data[i]; 
                        var optionstring = ""; 
                        for (var j = 0; j < jsonObj.length; j++) {
                            optionstring += "<option value=\""  + jsonObj[j].name + "\">" + jsonObj[j].name + "</option>"; 
                            $("#type").html("<option value=‘请选择‘  >请选择...</option>"+ optionstring);
                        } 
                      
                        
                    } 
                }, 
                error: function (msg) { 
                    alert("出错了！"); 
                } 
            });           
        }; 
         window.onload=addnotice; //页面加载完自动加载
    </script>