>Thanks Jim,
>This working when I created new form. But unfortunately not working on my required form. Incase I am putting same validation on lostfocus its validating. Although I solved my problem but still I am in digging why its not working on my form.

Sajjad,

If you want to find out why it doesn't work on your form, just comment out all of your valid code and then add it back in one line at a time until it doesn't work anymore, the last line you added in is the culprit.