hi,
in my app i have requirement something like this. i have one text box and attached on change event. when ever you key in say student number it will try to get the student details. and i have one add button. after getting student details when ever i click on add button that record will be added to bottom grid.

but here the problem is when ever user keys in invalid code and click on add button(here std code invalid and hence should not add to bottom grid) record adding to bottom grid.

here my requirement is when ever record is invalid i want to cancel add request.how can i do this

thanks,
ramki.