Validate to crate a new instance

Hello,

I have a plan page created in VS.NET with 3 plan buttons.

I would like to validate some data entered by users when each of these 3 buttons are clicked. The data validation is made by queries to the database.
If the data is invalid I just want to show a message informing the user which text field is not correct and do not create the K2 instance.

Is there any possible way of doing this?


Thanks in advance,
Liberto