public ActionResult Sample28()
        {
            // Check is data posted
            if (Request.HttpMethod == "POST")
            {
                //### Set variables and get POST data
                System.Collections.Hashtable result = new System.Collections.Hashtable();
                String clientId = Request.Form["clientId"];
                String privateKey = Request.Form["privateKey"];
                String fileId = Request.Form["fileId"];
                String basePath = Request.Form["basePath"];
                // Set entered data to the results list
                result.Add("clientId", clientId);
                result.Add("privateKey", privateKey);
                result.Add("fileId", fileId);
                String error = null;
                // Check is all needed fields are entered
                if (clientId == null || privateKey == null || fileId == null)
                {
                    // If not all fields entered send error message
                    error = "Please enter all parameters";
                    result.Add("error", error);
                    return View("Sample28", null, result);
                }
                else
                {
                    if (basePath == "")
                    {
                        basePath = "https://api.groupdocs.com/v2.0";
                    }
                    result.Add("basePath", basePath);
                    // Create service for Groupdocs account
                    GroupdocsService service = new GroupdocsService(basePath, clientId, privateKey);
                    // Get all annotations from document
                    Groupdocs.Api.Contract.Annotation.ListAnnotationsResult annotations = service.ListAnnotations(fileId);
                    // If annotations wasn't found return error
                    if (annotations.Annotations.Length == 0)
                    {

                        error = "File you are entered contains no annotations";
                        result.Add("error", error);
                        return View("Sample28", null, result);

                    }
                    Groupdocs.Api.Contract.Annotation.DeleteAnnotationResult delAnnot = null;
                    if (annotations.Annotations.Length != 0)
                    {
                        String message = "All annotations deleted successfully";
                        result.Add("message", message);
                        //Get annotations data
                        for (int i = 0; i < annotations.Annotations.Length; i++)
                        {
                            delAnnot = service.DeleteAnnotation(annotations.Annotations[i].Guid);

                        }
                    }
                    String url = "";
                    //iframe to prodaction server
                    if (basePath.Equals("https://api.groupdocs.com/v2.0"))
                    {
                        url = "https://apps.groupdocs.com/document-viewer/embed/" + fileId;
                        //iframe to dev server
                    }
                    else if (basePath.Equals("https://dev-api-groupdocs.dynabic.com/v2.0"))
                    {
                        url = "https://dev-apps-groupdocs.dynabic.com/document-viewer/embed/" + fileId;
                        //iframe to test server
                    }
                    else if (basePath.Equals("https://stage-api-groupdocs.dynabic.com/v2.0"))
                    {
                        url = "https://stage-api-groupdocs.dynabic.com/document-viewer/embed/" + fileId;
                    }
                    else if (basePath.Equals("http://realtime-api.groupdocs.com"))
                    {
                        url = "http://realtime-apps.groupdocs.com/document-viewer/embed/" + fileId;
                    }
                    //Set data for template
                    result.Add("url", url);
                    return View("Sample28", null, result);
                }

            }
            // If data not posted return to template for filling of necessary fields
            else
            {
                return View("Sample28");
            }
        }