consume asmx with ajax(outside the webservice layer)

Question

in my Solution I have several layers and one of them is the webservice, all pages that consume the webservice and are in the webservice layer work, but put in another layer of error in javascript.

    <table border="0">
        <tr>
            <td>
                Emp:
            </td>
            <td>
                <input id="txtEmp" type="text" />
            </td>
        </tr>
        <tr>
            <td>
                User:
            </td>
            <td>
                <input id="txtUser" type="text" />
            </td>
        </tr>
        <tr>
            <td>
                Pass:
            </td>
            <td>
                <input id="txtPass" type="text" />
            </td>
        </tr>
        <tr>
            <td>
                <!--<button id="btnSubmit1" value="button" type="submit"></button>-->
                <input id="btnSubmit1" type="button" value="button" />
            </td>
        </tr>
    </table>
    <div><table id="datagrid"></table></div>
</form>

<script type="text/javascript" src="http://ajax.googleapis.com/ajax/libs/jquery/1.8.3/jquery.min.js"></script>
<script type="text/javascript">
    $(function () {
        $("[id*=btnSubmit1]").click(function () {
            var emp = $.trim($("[id*=txtEmp]").val());
            var user = $.trim($("[id*=txtUser]").val());
            var pass = $.trim($("[id*=txtPass]").val());
            $.ajax({
                type: "POST",
                url: "Service.asmx/SELECT_ALL_CATEGORIAS",
                data: "{ EMP_ID: " + emp + ", UserName: '" + user + "', Password: '" + pass + "'}",
                contentType: "application/json; charset=utf-8",
                dataType: "json",
                success: function (data) {
                    debugger;
                    if (!data) {
                        alert('Fornecedor não encontrado. Por favor verifique e tente novamente.');
                    } else {
                        var tabela = $("#datagrid");
                        var rows = "";
                        tabela.find("tbody td").remove();
                       // var myData = data.d;
                        var myData = JSON.parse(data.d);
                        for (var i = 0; i < myData.length; i++) {
                            var obj = myData[i];

                            rows += "<tr>";
                            rows += " <td>" + obj.id + "</td>";
                            rows += " <td>" + obj.descricao + "</td>";
                            rows += " <td>" + obj.filial_id + "</td>";
                            rows += " <td> <input type='checkbox' /> </td>";
                            rows += "</tr>";
                        }

                       // tabela.find("tbody").html(rows);
                        tabela.html('<tbody>' + rows + '</tbody>');
                    }
                },
                error: function (data) {
                    debugger;
                    alert('Error');
                }
            });
            return false;
        });
    });
</script>

the layers I want you to consume the webservice are using the Cordova framework.