What you have to do instead is change the value in the editing control (remembering not to cancel the event).For example, for a Your response was great and saved me lots of time.
I tried and i get the answer to true won't allow user to leave current cell as long as value is not valid one.
Both Cell Validating and Row Validating events allow you to stop the commit process by setting the boolean property Is Valid to False.
The Cell Validating event occurs when a cell is about to commit new content.
1) Add a conditional statement in the event handler code to only execute when required.
2) Detach the event hander before the unwanted event triggers and re-attach after.