diff --git a/Sample.hs b/Sample.hs
new file mode 100644
--- /dev/null
+++ b/Sample.hs
@@ -0,0 +1,98 @@
+ module Main where
+-------------------------------------------------
+-- A example of Transactional cache usage (TCache.hs)
+-- (Something like the Java Hibernate)
+-- Author: Alberto Gómez Corona Nov 2006
+-- Language: Haskell
+-- Terms of use: you can do whatever you want
+-- with this code as long as you keep this notice
+------------------------------------------------
+
+import Data.TCache
+
+import Control.Concurrent
+import Debug.Trace
+
+debug a b= trace b a
+
+--1 and 4: The data elements to be used in the example: A user will repeatedly buy Items.
+
+data  Data=   User{uname::String, uid::String, spent:: Int} |
+              Item{iname::String, iid::String, price::Int, stock::Int}
+ 
+              deriving (Read, Show)
+
+--3 The mappings between the cache and the phisical storage are defined by the interface IResource
+
+--      to extract the resource unique key,
+
+--      to read the resource from the physical storage,
+
+--      to store it and
+
+--      to delete the resource from the physical storage.
+
+ 
+
+instance IResource Data where
+        keyResource         User{uid=id}= id
+        keyResource         Item{iid=id}= id        
+        serialize x= show x
+        deserialize x= read x
+        defPath _ = "data/"  -- directory where the data is stored.
+        
+        -- other definable methods: readResource, writeResource delResource. here the default persistence in files are used
+        
+-- buy is the operation to be performed in the example
+
+--4 withResources gets a partial definition of each resource necessary for extracting the key, fill all the rest of the data structures (if found ) and return a list of Maybe Data. BuyIt is part of the domain problem. it receive this list and generates a new list of dat objects that are updated in the cache. buyIt is executed atomically.
+
+
+user `buy` item=
+    withResources[user,item] buyIt
+
+ where
+
+    buyIt[Just us,Just it]
+       | stock it > 0= [us',it'] `debug` "john buy a PC"
+       | otherwise   = error "stock is empty for this product"
+       
+      where
+       us'= us{spent=spent us + price it}
+       it'= it{stock= stock it-1}
+
+
+    buyIt _ = error "either the user or the item does not exist"
+
+
+main= do
+        -- create resources (acces no resources and return two new Data objects defined in items)
+        withResources[]items
+
+        --11 PCs are charged  to the John´s account in paralel, to show transactionality
+        --because there are only 10 PCs in stock, the last thread must return an error
+
+        for 11 $ forkIO $ User{uid="U12345"} `buy` Item{iid="I54321"}
+        
+        --wait 5 seconds        
+        threadDelay 5000000
+
+        [us,it] <-  getResources [User{uid="U12345"}, Item{iid="I54321"}]
+        
+        print $  "user data=" ++ show us
+        print $  "item data=" ++ show it
+        
+        -- write the cache content in a persistent store (invoque writeResource for each resource)
+        -- in a real application clearSyncCache can be used instead to adjust size and write the cache periodically
+
+        syncCache (refcache :: Cache Data)
+
+        -- the files have been created. the files U12345 and I54321 must contain the result of the 11 iterations
+
+  where
+        items _=
+              [User "John" "U12345" 0
+              ,Item "PC" "I54321" 6000 10]
+              
+        for 0 _ = return ()      
+        for n f= f >> for (n-1) f
diff --git a/TCache.cabal b/TCache.cabal
--- a/TCache.cabal
+++ b/TCache.cabal
@@ -1,14 +1,14 @@
 name:                TCache
-version:             0.5
-synopsis:            A Transactional cache with configurable persitence 
+version:             0.5.1
+synopsis:            A Transactional data cache with configurable persitence 
 description:         -------------------------------------------------
 -- A Transactional data cache with configurable persitence
 -- The exported methods are documented in the TCache.hs header
--- See also  http://haskellandweb.blogspot.com
+-- See also  http://haskell-web.blogspot.com
 -- (Something like a little Java Hybernate or Rails for Rubi)
 -- Author: Alberto Gómez Corona Nov 2006-2008   agocorona at gmail.com
 -- Language: Haskell
--- Version: 0.5
+-- Version: 0.5.1
 -- Terms of use: you can do whatever you want
 -- with this code as long as you keep this notice