js使用ajax传值给后台,后台返回字符串处理方法

<code class="language-html"><input type="text" id="iusername" runat="server" onblur="tbox_click()"/> 
<input id="inadd" runat="server" type="text" /> 
<input id="intel" runat="server" type="text" /></code> 

<script>
  function tbox_click() {
   var cc = document.getElementById("iusername").value;
   var jsonob = {tbname:cc};
   $.ajax({
    type: "Post",
    url: "tc.aspx/Tbclick",
    contentType: "application/json; charset=utf-8",
    dataType: "text",
    data: JSON.stringify(jsonob),
    success: function (data) {
     var a = eval("(" + data + ")");
     var al = a.d;
     if (al == "namenull") {
      alert("The user name does not exist. Please re-enter it(该用户名不存在，请重新输入)");
      return;
     }
     if (al == "null") {
      alert("Please input OBTUsername(请输入用户名)");
      return;
     }
     //alert(a.d);
     var myd = new Array();
     myd = a.d.split("|");
     $("#intel").val(myd[0]);
     $("#inadd").val(myd[1]);
    },
    error: function (e) {
     alert(e.message);
    }
   });
  }
 </script>

[WebMethod]
  public static string Tbclick(string tbname)
  {
   if (tbname.Trim() == "")
   {
    return "null";
   }
   var user = new User(tbname.Trim());//这个是根据tbname从数据库中获取信息的方法，可以自行填写
   if (user.userName == null)
   {
    return "namenull";
   }
   string jsonText = user.mobile+"|"+user.address;
 
   return jsonText;
  }

var aa = eval("(" + data.d + ")");
alert(aa);

var a = eval("(" + data + ")");
alert(a.d);