var p = new Object();
                p.Summ = $("#txtSumm").val();
                p.Recharge = $("#txtReCharge").val();
                //p.------ = $("#контрол").is(':checked') ? true : false;
                p.Currency = $("#ddlCurrency option:selected").val();
                p.Months = $("#ddlMonth option:selected").val();

                $.ajax({
                    type: "POST",
                    contentType: "application/json; charset=utf-8",
                    dataType: "json",
                    cache: false,
                    url: "http://localhost:10160/url.asmx",
                    data: "{'p':" + JSON.stringify(p) + "}",
                    success: function (dat) {
                        
                    },
                    error: function (xhr, ajaxOptions, thrownError) {
                        alert(thrownError;
                    }
                });

[WebService(Namespace = "")]
[ScriptService]
public class TestService : System.Web.Services.WebService {
    [WebMethod]
    [ScriptMethod(ResponseFormat = ResponseFormat.Json)]
    public ObjectClass WebGetMethod(ClassParams p)
    {
        ObjectClass data = new ObjectClass();
        data = LoadData(p);
        return data;
    }

}