Form validation

[Anon]

I am having some problem with form validation. I know how to limit the number of characters entered into my form fields using the maxlength in HTML, BUT, if someone saves the form to their HD, strips out those HTML limiters and re-posts the form with loads of data in the fileds, the processor usage on the webserver is eaten up totally.
any ideas of how to resolve this?
Heres the line

$strsubject = "<input class=formfield type=text size=35 maxlength=255 name=subject value=\"".htmlspecialchars(stripslashes($subject))."\">";

[Anon]

Your Processing page can check the length of the varrious inputs and then you can return to the form page if the input data in not valid. Since this all happens server-side the user cannot tamper with it. You do have to settle for the fact that you would be verifying the same data twice in most instances, but the tradeoff might be worth the processing time if it is exceptionally important.

[Anon]

What I did in the end was to put a strlen on the variable so it would only process that number of chars. It seems to have fixed the problem,
thanks,
Paul.

kilroy wrote:

Your Processing page can check the length of the varrious inputs and then you can return to the form page if the input data in not valid. Since this all happens server-side the user cannot tamper with it. You do have to settle for the fact that you would be verifying the same data twice in most instances, but the tradeoff might be worth the processing time if it is exceptionally important.