函数以及ajax方法使用

//查询
 function queryInfos(page){
  currentPage = page;
  var applycompany = $('#applycompany').val();
  var uniscidOrRegno = $('#uniscidOrRegno').val();
  var legalperson = $('#legalperson').val();
  var address = $('#address').val();
  var obj = document.getElementsByName("unitGrade");
  var unitGrade = "";
  for(var i = 0; i < obj.length; i++){
   if(obj[i].checked){
    unitGrade += "'" + obj[i].value+"',";
   }
  }
  var state = $('#state').val();
  var selectedvalue = $("input[name='queryType']:checked").val();
  $.ajax({
   url : rootPath + "/GradeChangeQueryAction.do",
   data : {
    applycompany: encodeURI(applycompany),
    uniscidOrRegno: uniscidOrRegno,
    legalperson: encodeURI(legalperson),
    address: encodeURI(address),
    unitGrade:unitGrade,
    state:state,
    selectedvalue:selectedvalue,
    pageNum: currentPage,
    pageSize: recordPage
   },
   type : "post",
   dataType : "json",
   beforeSend: function() {
    $('#list_data').datagrid('loadData', []);
   },
   success : function(request) {
    if (request) {
     var data = eval(request);
     if (data.returnDm == "0") { //返回正常
      counts = data.returnData.total;
      if(counts == "0"){
       alert("查询结果为空！");
      }
      initPagination();
      //加载查询结果数据
      $("#list_data").datagrid("loadData",data.returnData);
     } else {
      var returnMessage = data.returnMessage;
      if (returnMessage == "") {
       alert("查询异常!");
      } else {
       alert("查询异常："+returnMessage);
      }
     }
    }
   },
   error : function() {
    alert("查询失败，请稍候重试!");
   }
  });
 }