Metin,

>And I think so your method recude interactivity in forms like a web browser app.

I don't think it's crude by any means. The user can freely move around the form working in a field order that might be vastly different than the tab order of the form. As they save the form, the validation puts focus right back to the control where the error occurs.

I think this is much better than a control valid that will not let the user out of the control especially when what the user needs to do at this instant is enter data in some other field.