Asp.net Webform page implementing jQuery Autocomplete Widget - asp.net

Question

I want to incorporate jquery autocomplete widget to my aspx page. The "source" for the autocomplete comes from a webservice method.
My script looks like this:
$(".paisProc").autocomplete({
minLength: 0,
source: function (request, response) {
$.ajax({
type: "POST",
url: "/ManifestService.asmx/GetPaises",
dataType: "json",
contentType: "application/json; charset=utf-8",
data: JSON.stringify({ 'term': request.term }),
success: function (data) {
console.log("reading results...");
response($.map(data, function (item) {
console.log(item.CodigoAduana);
return {
label: item.Descripcion,
value: item.CodigoAduana
};
}));
},
error: function (err, status, error) {
console.log(status);
console.log(error);
}
});
With this setup, as users type in the input control, the expected values are returned from the webservice but the autocomplete does not seem to work. Inspecting the page with Firebug i see the ajax call to the service returns data with this format:
{"d":[{"__type":"dhl.domain.Pais","PaisId":1,"CodigoDHL":"AR","CodigoAduana":"528","Descripcion":"ARGENTINA"},
{"__type":"dhl.domain.Pais","PaisId":481,"CodigoDHL":"DZ","CodigoAduana":"208","Descripcion":"ARGELIA"}]}
I cannot see what the problem with my code, I have followed the indications from the many questions with the same issue in this site with no success yet.
If it can help, the line console.log(item.CodigoAduana) from success callback write "undefined" to the console.

Answer 1

.Net web services returning JSON do so by embedding the payload into a "d" property (as you can see in your capture of the JSON).
Try changing your processing of the response to read from data.d instead of just data, to get to the array you want to map, like this:
response($.map(data.d, function (item) {
console.log(item.CodigoAduana);
return {
label: item.Descripcion,
value: item.CodigoAduana
};
}));