c# – jQuery,ajax POST方法成功返回：未定义

$('#btnSave').click(function() {
    var pageUrl = '<%= ResolveUrl("~/TestPage.aspx/SystemEdit")%>';
    var ip = $('#editIP').text();
    var loc = $('#txtBay').val();
    var team = $('#txtTeam').val();
    var port = $('#txtPort').val();
    var xcel = "",office = "",moni = "";                                   
    var parameter={ "ip": ip,"loc": loc,"team": team,"port": port,"excel": xcel,"office": office,"monitor": moni}

    $.ajax({
        type: 'POST',url: pageUrl,data: JSON.stringify(parameter),contentType: 'json',success: function(data) {
            alert(data);
        },error: function(data,success,error) {
            alert("Error:" +error);
        }
    });           
});

我在c#代码后面的代码是：

[WebMethod]
public static string SystemEdit(string ip,string loc,string team,string port,string excel,string office,string monitor)
{
    return "The Current Time is: "+ DateTime.Now.ToString();
}

我的页面名称是：TestPage.aspx

单击保存按钮时,我’未定义’.我没有从c#后面的代码中获取当前时间.