Control form submit error

I've got a large form which submits to a .php on the server to store the results. The problem I have is that if there's a problem calling the .php, I don't know how to handle it. I mean, if there's a problem I want to be able to let the user retry the submit.

I've looke all over the place and can't find how to do this. Can anyone help, please?

What kind of problem submitting? Missing values from the form that need to go to the script?

No. I mean what happens if just at the moment I send the script there are communication problemas or whatever and the values just don't get sent to the server.

that will nearly never happen, that would meen that at the moment that the user submits the form his internet conection closes. and if that would happen no one can do anything against that. he would have to get a new connection to the internet and then try again

OK. But exactly what I'd like to know is if there is any way to detect that this has happened and try again.

Just save this script as test.php, and run it to see what happens.

The user could always press the back button. You are talking about a physical connectivity problem. You really don't have anything to worry about in the way of storing the values in case something happens. If this goes on a lot on your server, there are bigger problems at hand, and I would address those first.

Well, just to explain my problema a little more and see if anyone has any ideas. Our system does personality tests for personnel selection. Some of the tests are very long (300+ questions) and usually there will be 20 or more people doing the same test at the same time. Of course, anything can go wrong just when the user presses the submit button. As we can't count on our clients having good internet connections, or on the users being computer-wise, when there's a problem it cuases great distress. What usually happens is they get a 404 error or similar because the php which receives the values cannot be run. All I'd like to be able to do is know whether the submit has been succesful so that I can then present a friendly screen which says "Try again" or whatever.