diff --git a/composer/report/field.py b/composer/report/field.py
index 4debe38..6257e00 100644
--- a/composer/report/field.py
+++ b/composer/report/field.py
@@ -1,5 +1,5 @@
 #
-#  Copyright (c) 2010 Helmut Merz helmutm@cy55.de
+#  Copyright (c) 2012 Helmut Merz helmutm@cy55.de
 #
 #  This program is free software; you can redistribute it and/or modify
 #  it under the terms of the GNU General Public License as published by
@@ -18,8 +18,6 @@
 
 """
 Implementation of report field definitions.
-
-$Id$
 """
 
 from datetime import datetime
@@ -93,6 +91,14 @@ class Field(Component):
         #return self.getValue(row)
 
 
+class CalculatedField(Field):
+
+    def getRawValue(self, row):
+        return getattr(row, self.name)
+
+
+# sample field
+
 label = Field('label', u'Label',
                 u'A short text that identifies a row for humans.')
 
diff --git a/composer/report/result.py b/composer/report/result.py
index 9af877f..4401563 100644
--- a/composer/report/result.py
+++ b/composer/report/result.py
@@ -33,6 +33,7 @@ class BaseRow(object):
         self.context = context
         self.parent = parent
         self.data = {}
+        self.sequenceNumber = 0
 
     def __getattr__(self, attr):
         f = self.parent.context.fields[attr]
@@ -71,6 +72,8 @@ class ResultSet(object):
         result = [row for row in result if self.queryCriteria.check(row)]
         if self.sortCriteria:
             result.sort(key=lambda x: [f.getSortValue(x) for f in self.sortCriteria])
+        for idx, row in enumerate(result):
+            row.sequenceNumber = idx + 1
         return result
 
     def __iter__(self):