Need help on refresh

Hello,

i’ve got a really nasty problem here.
I saw there are some solutions here in the forum but i didn’t get anything to work properly.

This is my problem.

When i submit a page i use a form with some data in hidden fields:
act=“insert”

this works fine. When the page is submitted it calls itself and sees the posted action and inserts a record in the database.

But now i pushed the refresh button. And it keeps inserting a record for every refresh.
this is not what i want. I tried to set the action on the hidden field to “” but that doesn’t help.
Setting the no-cache in the header didn’t help eather. Using a session var could be possible but i don’t understand how to do this.

any help would be greatly appreciated…
thx in advance.