bootstrap 下拉选中查询

<div class="form-group">
                   <label class="col-lg-3 col-sm-2 control-label">资源种类</label>
                                    <div class="col-lg-9">
                                        <select id="item1" onchange="fn()" name="resource" 
                                           class="form-control m-bot15"     placeholder="请选择" style=" 200px;">
                                                    <option value="">请选择</option>
                                                    <option value="服务器">服务器</option>
                                                    <option value="内存">内存</option>
                                                    <option value="存储">存储</option>
                                                    <option value="其他">其他</option>            
                                        </select>
                                    </div>
                                </div>

function  fn(){
       var   name=$("#item1").find("option:selected").val(); 
           if(name !==null){
               resource=name;
           }
    };
//查询参数
function queryParams(params) {
            var search={};
            $.each($("#searchform").serializeArray(), function(i, field) {  
                   search[field.name] = field.value; 
            })
            var filters=JSON.stringify(search);
            var dataObj=eval("("+filters+")");
           var str={"page":this.pageNumber,
                    "pageSize":this.pageSize,
                    "filter":{"filters":[{"field":"resource","value":dataObj.resource}]},
                    "sort":[{"field":"name","dir":"ASC"}]}; 
            var baseData = JSON.stringify(str); 
             var param = {
                     models :baseData
                 }
            return param;
            }