private static void CleanEmptyFields(bool cleanEmptyFields, IMLSection section)
        {

            if (!cleanEmptyFields) 
                return;

            //Importer.CurrentProgress++;
            MainImportingEngine.ThisProgress.Progress
                (MainImportingEngine.CurrentProgress, 
                "Cleaning empty library fields...");
            //Thread.Sleep(800);

            string[] tagNames = section.GetTagNames();


            section.BeginUpdate();

            foreach (string tagName in tagNames)
            {
                bool allTagValuesAreEmpty = true;

                //Importer.thisProgress.Progress(100, TagName);
                //Thread.Sleep(1000);

                if (tagName == "ToDelete")
                {

                }

                if (section.GetTagValues(tagName) == null) continue;

                string[] TagValues = section.GetTagValues(tagName);

                foreach (string tagvalue in TagValues.Where(tagvalue => !String.IsNullOrEmpty(tagvalue)))
                    allTagValuesAreEmpty = false;


                if (allTagValuesAreEmpty)
                    section.DeleteTag(tagName);

            }
            section.EndUpdate();


            section.BeginUpdate();

            //Importer.CurrentProgress++;
            MainImportingEngine.ThisProgress.Progress
                (MainImportingEngine.CurrentProgress, 
                "Removing items marked for deletion...");
            
            Thread.Sleep(800);

            IMLItemList itemsToDelete = section.SearchByTag("ToDelete", "true");
            
            foreach (IMLItem t in itemsToDelete)
                section.DeleteItem(t);

            section.EndUpdate();

        }
        private static void CleanUserFields
            (IMLSection section, bool cleanSelectedFields, string selectedFieldsToClean)
        {

            if (!cleanSelectedFields) 
                return;

            //Importer.CurrentProgress++;
            MainImportingEngine.ThisProgress.Progress
                (MainImportingEngine.CurrentProgress, 
                "Cleaning user-specified library fields...");
            
            Thread.Sleep(800);


            section.BeginUpdate();

            string[] fieldsToClean = selectedFieldsToClean.Split(',');

            foreach (string fieldtoclean in fieldsToClean)
                section.DeleteTag(fieldtoclean.Trim());

            section.EndUpdate();

        }