How to write validation
As per my client requirement I have to write one validation like if postings should not happen more than the 2 days ago of current date.
Eg if Posting date is 20.05.2011
system should not allow postings less than 2 days of 20.05.2011 means which allow upto 19.05.2011 and 18.05.2011.
please give any suggestions how to write validation for it