Simple Question

[rubric]

I hope this is a simple one to answer, and I'm pretty sure everone has gone through this.

When a user is on my site and he/she does things back and forth, everynow and then he/she will hit the back button and a previously done action occurs again.

Let's say the user sends a message to another user through an interface I wrote, but after it's sent, the user clicks the back button and the message is sent again! Also, and I know most of you have seen this, the user will get the infamous "Page Expired" error and is instructed to refresh the page by sending the post variables again.

How do I control this? How can I make sure that the back button will not have a previously done action happen again?

[ereptur]

Well, there are basically two things that you can do to remedy this. One is to use an in-between page, such as a user post a message to another user, it goes a posting script then that posting script redirects them back to where they were.

The second thing that seems to help is to put plenty of links to all of the sections of your site, so users are more likely to use those links rather than their browser functions.

[planetsim]

To get rid of that. You could see if submit is pressed twice.

Other than that. You cant really get rid of it. Its a security thing for the browser.