Yesterday I was working on a page where a user is inserting some things in the MySQL table.
When everything is done, they are sent to another page. But I saw that it updates everything again if I click the back button on my browser.
So I put a little code there saying that $updated=1 and then I put that on top of the first page checking if $updated=1, then the user should be transferred away with a header Location code.
But even that didn't work. The stuff were updated anyway.

Never thought about that before... but is it common or is there a solution to solve it?