diff --git a/lib/compare_lists.py b/lib/compare_lists.py
index c630847..516cfb8 100644
--- a/lib/compare_lists.py
+++ b/lib/compare_lists.py
@@ -32,16 +32,23 @@ def compareFiles(rdDataBasePath, jsonPath, sivasId, outPath):
 if __name__ == '__main__':
     parser = argparse.ArgumentParser(description='fetches data from sivas or ruledesigner fusion', prog='update_database')
     parser.add_argument('-s', '--sivas', action='store', help='fetch data of this id from sivas fo local database folder')
+    parser.add_argument('-d', '--database', action='store', default="RD_Bestandspool.csv", help='local filename of the latest fetched RuleDesigner Database')
 
     args = parser.parse_args()
 
-    dataDir = os.environ.get('CREMIG_DATA')
-    rdDataBasePath = os.environ.get('RD_DATABASE_SOURCE')
+
     if args.sivas:
+        # fetching the names  of all existing cad files from the local file
+        dataDir = os.environ.get('CREMIG_DATA')
+        rdDataBasePath = os.path.join(dataDir, args.database)
+        # get the path to ask for further json files
         exePath = os.environ.get('SIVAS_DATABASE_QUERY')
+        # in case the infos for this cad file are already there
         sivasId = str(args.sivas)
         jsonPath = os.path.join(dataDir, sivasId + ".json")
+        # there the results are written
         outPath = os.environ.get('CREMIG_WORK')
+        
         compareFiles(rdDataBasePath, jsonPath, sivasId, outPath)