User exit/ BADI for transaction VF11

Dear Gurus,

My requirement is that, When a billing document is canceled using transaction code VF11, while saving the document, a information message needs to be displayed based up on the invoice date which is currently getting canceled.

Kindly help me out with User Exit / BADI while saving and the table fields which will have invoice date of the invoice which is getting canceled.

Thanks,

Bhupender Dangi