Help whit ERP

I should work ERP apllication fro Windows mobile pro 6 , compitable whit Sql Compact 3.5 all is ok , but when i add any new data whit button on dataGrid , all is ok valuses is added but when i close Form and click again on same Form new added data is lost how to make to save it there?

here is video of problem http://www.youtube.com/watch?v=3OQ83b9rWpQ

Are you saving your data to the database? It seems that you just adding data to the grid and not saving it in the database.