How to Bind ul li tag using jquery in asp.net C#

Question

have written this code but not getting result as i want. data is not showing in ul li but when running webservice getting all data as it is in db.   please help me

javascript code is

$.ajax({

type: "POST",

url: "userControls/Wsc_comn.asmx/BindCategory",

data: "{}",

dataType: "json",

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

async: true,

success: OnSuccess,

error: OnError

});

function OnSuccess(data) {

$.each(data, function(key, value) {

$("#tablet").append("<li><a rel='external' href='" + this.attachment_url + "'>" + value.Product_name + "</li>");

});

}

function OnError(data) {

}

 

 

c# code

 

 

[WebMethod]

[ScriptMethod(UseHttpGet = false, ResponseFormat = ResponseFormat.Json)]

public string BindCategory()

{

string qry = "select *from products where Product_type='TABLETS'";

DataTable dt = dllmain.ExecuteselectQry_returns_datatable(qry);

foreach (DataRow row in dt.Rows)

{

string urls = row["attachment_url"].ToString();

string catname = row["Product_name"].ToString();

}

return dllgetinfo.getdatatabletojson(dt);

}