How to do the checking if a datagrid being changed or not ??

From the documentation: Data sources are further managed by BindingManagerBase objects. For each table in a data source, a BindingManagerBase can be returned from the form's BindingContext. For example, you can determine the number of rows contained by a data source by returning the associated BindingManagerBase object's Count property. To validate data, use the underlying objects that represent data and their events. For example, if the data comes from a DataTable in a DataSet, use the ColumnChanging and RowChanging events. OR When you load the data, have a count of the number of rows in datatableCustomer. Then when you the form closes (something like closing), check for the number of rows in datatableCustomer. Any change is because of user changes. HTH.