title: How to get JSON response from a 3.5 asmx web service
body: <p>I have the following method:</p>
  
  <pre><code>using System.Web.Services;
  using System.Web.Script.Services;
  using System.Web.Script.Serialization;
  using Newtonsoft.Json;
  using System.Collections;
  
  [WebService(Namespace = "http://tempuri.org/")]
  [WebServiceBinding(ConformsTo = WsiProfiles.BasicProfile1_1)]
  //[System.ComponentModel.ToolboxItem(false)]
  [System.Web.Script.Services.ScriptService]
  
  // [System.Web.Script.Services.ScriptService]
  public class Tripadvisor : System.Web.Services.WebService {
  
      public Tripadvisor () {
  
          //Uncomment the following line if using designed components 
          //InitializeComponent(); 
      }
  
  
      [WebMethod]
      [ScriptMethod(ResponseFormat = ResponseFormat.Json)]
      public string HotelAvailability(string api)
      {
          JavaScriptSerializer js = new JavaScriptSerializer();
          string json = js.Serialize(api);
          //JsonConvert.SerializeObject(api);
          return json ;
      }
  </code></pre>
  
  <p>Here i set ResponseFormat  attribute is json s still being returned as XML.</p>
  
  <p>I want to json format using this asmx service 
  Any ideas?</p>