refresh browser without resubmitting

After submitting a comment on this forum, the browser refresh button (I'm using FF) refreshes the page without resending the data.

How is this achieved?

maybe they submit the form with ajax

You are thinking of $_POST but if you look in hte address bar they are using $_GET. The data is in the URL so there is no data to send.

Yep, I was thinking of $_POST. Of course it's $_GET here!
D'oh!

I should be more observant. ;)

Thanks.