delete persist variable?

Hello Ray,
I use the persist data on a form so that the user doesn't need re-enter the data when the form submit fails.
But after successful submit I need to delete the form data. How can I do this whitout deleting all session variables?
Is there a way to get all of persist data session variables names?
TIA
tony

The session variable is named: "WASF_" + persistent form name. So you can just delete that one session variable on the success page.

Thanks, Ray,
It seems that I cannot delete a single variable (WASF_data_scontrino_sco) , but I can delete the whole array (WASF_persist_partecipa) that it's fine too.
But just out of curiosity, how can I delete a specific persist varibale?
TIA
tony

You would have to hand code it, but you can use:

<?php

unset($_SESSION["WASF_data_scontrino_sco"]["fieldname"]);

?>

Thanks, Ray.