Update in grid with validation

I have a paging datagrid which lists all user records.
Each of these records contains an integer field called "orderby".

I need to allow the users of the system to enter an integer into these boxes, validate the entry and in the onclick event of a button write these away.

When it comes down to updating in a datagrid with validation I always get lost.

Can anyone point me towards any decent examples on the web. This is driving me crazy !

All you have to do is create your own template column for the datagrid and embed one of the validator controls (required, compare, regex, etc).