how do i read c# list using java script

Question

here is my web service method(c#)

[WebMethod]

public List<Errors> GetPostings()

{

string connetionString = null;

SqlConnection cnn ;

connetionString = "Data Source=WIN-B5SQAAB3195.\\SCOM;Initial Catalog=Portal;Integrated Security=True";

cnn = new SqlConnection(connetionString);

const string SQL = "select dates,value from errors";

SqlCommand myCommand = new SqlCommand(SQL, cnn);

cnn.Open();

myCommand.ExecuteNonQuery();

// myConnection.Close();

SqlDataAdapter dataAdapter = new SqlDataAdapter();

dataAdapter.SelectCommand = myCommand;

DataSet DSet = new DataSet();

dataAdapter.Fill(DSet);

List<Errors> errors = new List<Errors>();

foreach (DataRow row in DSet.Tables[0].Rows)

{

Errors jp = new Errors();

jp.date = (DateTime)row["DATES"];

jp.values = (int)row["value"];

//jp.Id = (int)row["Id"];

//jp.JobPost = row["JobPosting"].ToString();

//jp.Applicant = row["Applicant"].ToString();

//jp.Type = row["Type"].ToString();

errors.Add(jp);

}

return errors;

}

here is my java script which has to read the list which is returned by the above code

$(function () {

$('#Button1').click(getPosts);

});

function getPosts() {

OpenEMRWebService.Service1.GetPostings();

try {

$.ajax({

type: "post",

url: "Service1.asmx/GetPostings",

data: "{}",

contentType: "application/json; charset=utf-8",

dataType: "json",

success: function (response) {

var jposts = response.d;

$('#output').empty();

$.each(jposts, function (index, jpost) {

$('#output').append('<p><strong>Job Posting: ' + jpost.dates + '</strong><br />Job Id: ' +

jpost.value + '<br />Internal/External: ' +

'</p>');

});

},

failure: function (msg) {

$('#output').text(msg);

}

});

}

catch (e) {

alert(1);

}

}

but it not returning any values  can any one help doing this?

thanx in advance