Executing The Function Only Once (For Captcha)

[mostafatalebi]

Hello everybody

I have a problem in my form submission which I think could be easily solved by a pro programmer

 

Setting:

I have a form

At the end of the form I have put something like a CAPTCHA. There is a question, and a text input for the user to enter the answer.

So far everything works fine, the question is randomly generated without any problem.

 

But as soon as the user clicks on the submit button, the script regenerates the question which naturally has a different answer than the one the user has entered. What should I do to avoid execution of the function when the form is submitted??

 

However if somebody likes to see the script architecture here it is:

 

function randomSentenceGenerator ()
{
php script
}
$question_and_answer_array = randomSentenceGenerator();
if(isset($_POST['submit'])
{
if(question != answer)
{
tell user to enter a correct answer
}
Include the HTML
}
else
{
include the HTML
}

Edited January 1, 2013 by mostafatalebi

[Jessica]

You'll need to store the correct answer in the session and use that one to check your form. 

[mostafatalebi]

I have done this. But the problem is when the user submit the form the session updates to the new value

[Jessica]

You have a logic problem then. You need to see if the form is submitted before replacing the session value. 

[mostafatalebi]

logic is the same as you expect, but still doesn't

[kicken]

logic is the same as you expect, but still doesn't

 

Your logic is not as one would expect, it is incorrect.  Using your above template as an example, the correct logic flow would be something like:

function randomSentenceGenerator ()
{
php script
}




if(isset($_POST['submit'])
{
if(question != answer)
{
	tell user to enter a correct answer
}
Include the HTML
}
else
{
$question_and_answer_array = randomSentenceGenerator();
include the HTML
}

 

You generate a question only if the form was not submitted (or, optionally, if they answer incorrectly). When the form has been submitted you compare the post'ed answer with the answer in the session.