title: toJSON "Object doesn't support this property or method"
body: <p>I've a Javascript Class and its method. But when i call it toJSON is generating an error. I couldn't figure out why this error is happening.</p>
  
  <pre><code>try {
      if (this.TabloEkId == undefined || this.TabloEkId == "") {
          throw errEksikVeri;
      }
  
      fAjaxSetup(fBefore, fSuccess, fError, fComplete);
  
      $.ajax({
          type: "POST",
          contentType: "application/json; charset=utf-8",
          url: ResolveUrl("~/Yonetim/WS/Yonetim.asmx/f_TabloEklerindenSil"),
          data: "{_tblEkId:" + this.TabloEkId + "}",
          dataType: "json"
      });
  
  } catch (err) {
      f_ErrorViewer(err);
  }
  </code></pre>
  
  <p><img src="https://content.screencast.com/users/uzay95/folders/Jing/media/f8fc6a4f-b496-44ef-a592-d29f41c7c858/jsClass.png" alt="Javascript Class"></p>
  
  <p><img src="https://content.screencast.com/users/uzay95/folders/Jing/media/241d2521-a08c-4648-991e-78a58c69ab2e/jsClassMethod.png" alt="Error"></p>