Most simple solution is often do the thing you want with the posted data
in it on the receiving page (use PHP sessions if the data has to 'live
meta thingy) to another (or possibly the same page). Posts are 'lost' on
redirects, so no data will be resubmitted on refresh, the browser will go
straight to the page you provided.
As this is not really an HTML but PHP related issue (well, at least the
solution is), I've taken the liberty to post this answer to that group,
and set the follow-up to it.