Please keep all replies on-list so that others can benefit.
The way the ErrorProvider mechanism works is to validate the controls when the user sets focus away from them.
For instance, let's say you have a form in which you have the user enter a name and address. You would enable validation on the fields that you would want to perform data validation on to insure that the user entered correct data (valid address, valid state, etc). As the user entered the data and hit tab to go to the next field, that field will be validated.
So, the validation is not going to get called until the user goes to the next field. Any error condition from a previous check will remain until the validation call is done again.
...Glenn
Dear Glenn
Yeah it doesn't work.Another problem is that you said user must
attempt to set focus away from the contol.Do you know what should I do
to overcome these problems?