> The problem I am having is that people are double-submitting certain > transactions. My first attempt to prevent this was to store a flag in the > session record indicating whether or not certain transactions had been > completed, but this turned out to be insufficient at times because users > could try and initiate a second transaction before the first transaction had > finished (and thus the system had not yet flagged the transaction completed > in the session record). They then both completed in parallel, and voila, > duplicate transactions again. > > I realized that this sort of problem would always exist unless I had some > sort of semaphore mechanism. Once a user has *started* a transaction, they > need to be prevented from initiating a second transaction until the first > transaction has been completed. > > I am open to suggestions on how to do this. What is the best way? do you have access to a database? why not just manage the transaction on the database level? transactions, locking, etc. are a core part of what databases do for a living. it's not a problem best solved with PHP. /josh w -- PHP General Mailing List (http://www.php.net/) To unsubscribe, visit: http://www.php.net/unsub.php