verifyimg.php bug?

[jakobkramer]

Hi,

First off: I'm no PHP expert.

I have downloaded the formmail.php as well as the verifyimg.php code and uploaded both to my homepage (without modifications except at the places where it's "allowed", that is, for instance by setting a "true" to "false" in the configuration). Everything works fine.

However, I have noticed that I can provoke an error if I use the browser's back button after having sent a form. If I do this and choose "new image" a few times at the picture created by verifyimg.php, I can (re)send the form but get an error message saying that the text entered doesn't match the image's text - even though it DOES match the text. Sometimes it goes even further, and I get an error text saying something along the lines of "this form doesn't work - try contacting us in another way". If I then use the browser's reload button, everything usually works fine again.

Of course I should just not use the back button to go back to the form page (and how many people send multiple forms this way?), but it still bugs me, since I would of course prefer that the visitors at my homepage do not encounter any error messages.

Do any of you have an idea how to solve this problem?

Jakob Kramer

[jakobkramer]

Perhaps I should add, that this bug occurs both with the original verifyimg.php scrips as well as with the modified script mentioned in this thread:
http://www.tectite.com/vbforums/showthread.php?t=1279

[jakobkramer]

I think I may have narrowed down the culprit.

In all my tests, I have used the javascript and "renew code" feature described in the link in my previous post. I have now tried simply removing this part (that is, the visitor is given a code, but has no possibility to renew this), and as far as I can tell, everything works fine. At least I haven't had any error messages when sending approx. 15 test messages.

It seems (although I may be wrong since I'm not a skilled programmer myself) that the error is connected to the way the javascript and the verifyimg.php script interact.

As for now, I will just avoid making the image created by verifyimg.php too distorted and have faith in the eyesight of my visitors