projinvoice validation

In ax2009 to do validation while proj invoice posting updatenow method on projFormLetter_Invoice class was used…am not aware in ax2012 could any one ple help me wer can i add my validation code in that projFormLetter_invoice class

The logic has been re-factored, \Classes\ProjInvoiceJournalPost will do the posting job now.

\Classes\ProjInvoiceJournalPost\endPost

\Classes\ProjInvoiceJournalPost\endLines

thank you…