Adding CAPTCHA to Contact Form

[Fidel_Castro]

Hi,

I just got some nice Contact Form I would like to use on my website.

The only thing I would like to change is the verification code.

The one used in that contact form is too simple with only one question [How much is 2+3?].

I found a nice Captcha from another Contact Form and I was wondering if it is possible just to add that CAPTCHA to my actual Contact Form?

I tried but I didn't succeed.

This is my actual Contact Form PHP file:

<div class="Kforma">
            <?php
                 $error    = ''; // error message
                 $name     = ''; // sender's name
                 $email    = ''; // sender's email address
                 $subject  = ''; // subject
                 $message  = ''; // the message itself
               	 $spamcheck = ''; // Spam check

        if(isset($_POST['send']))
        {
             $name     = $_POST['name'];
             $email    = $_POST['email'];
             $subject  = $_POST['subject'];
             $message  = $_POST['message'];
           	 $spamcheck = $_POST['spamcheck'];

            if(trim($name) == '')
            {
                $error = '<div class="errormsg">Unesite Ime i Prezime</div>';
            }
        	    else if(trim($email) == '')
            {
                $error = '<div class="errormsg">Unesite e-mail adresu</div>';
            }
            else if(!isEmail($email))
            {
                $error = '<div class="errormsg">Netacan oblik e-mail adrese</div>';
            }
        	    if(trim($subject) == '')
            {
                $error = '<div class="errormsg">Unesite naslov poruke</div>';
            }
        	else if(trim($message) == '')
            {
                $error = '<div class="errormsg">Unesite poruku</div>';
            }
          	else if(trim($spamcheck) == '')
            {
            	$error = '<div class="errormsg">3+2=?!</div>';
            }
          	else if(trim($spamcheck) != '5')
            {
            	$error = '<div class="errormsg">Netacno! 2 + 3 = ???</div>';
            }
            if($error == '')
            {
                if(get_magic_quotes_gpc())
                {
                    $message = stripslashes($message);
                }
                $to      = "[e-mail]";

                $subject = 'Poruka sa neta : ' . $subject;

                // the mail message ( add any additional information if you want )
                $msg     = "\r\n$message";

                mail($to, $subject, $msg, "From: $name\r\nReply-To: $email\r\nReturn-Path: $email\r\n");
        ?>
              <div style="text-align:center;">
                <h1>Hvala!</h1>
                <b><?=$name;?></b>, Vasa poruka je uspjesno poslata. Uskoro bi trebali da dobijete odgovor.</p>
              </div>


        <?php
            }
        }

        if(!isset($_POST['send']) || $error != '')
        {
        ?>
        <?=$error;?>

        <form  method="post" name="contFrm" id="contFrm" action="">


<b>Ime i Prezime:</b><br /><input name="name" type="text" class="box" id="name" size="30" value="<?=$name;?>" /><br><br>

<b>E-mail adresa:</b> <br /><input name="email" type="text" class="box" id="email" size="30" value="<?=$email;?>" /><br><br>

<b>Naslov poruke:</b> <br /><input name="subject" type="text" class="box" id="subject" size="30" value="<?=$subject;?>" /><br><br>

<b>Poruka:</b> <br /><textarea name="message" cols="60" rows="10"  id="message"><?=$message;?></textarea><br /><br><br>

<b>Koliko je:</b> <b>2 + 3=</b> <input name="spamcheck" type="text" class="box" id="spamcheck" size="4" value="<?=$spamcheck;?>" /><br /><br />


<input name="send" type="image" src="Kontakt/contact_images/submit.gif" class="button" id="send" value="Posalji poruku" />


        </form>


        <?php
        }

        function isEmail($email)
        {
            return(preg_match("/^[-_.[:alnum:]]+@((([[:alnum:]]|[[:alnum:]][[:alnum:]-]*[[:alnum:]])\.)+(ad|ae|aero|af|ag|ai|al|am|an|ao|aq|ar|arpa|as|at|au|aw|az|ba|bb|bd|be|bf|bg|bh|bi|biz|bj|bm|bn|bo|br|bs|bt|bv|bw|by|bz|ca|cc|cd|cf|cg|ch|ci|ck|cl|cm|cn|co|com|coop|cr|cs|cu|cv|cx|cy|cz|de|dj|dk|dm|do|dz|ec|edu|ee|eg|eh|er|es|et|eu|fi|fj|fk|fm|fo|fr|ga|gb|gd|ge|gf|gh|gi|gl|gm|gn|gov|gp|gq|gr|gs|gt|gu|gw|gy|hk|hm|hn|hr|ht|hu|id|ie|il|in|info|int|io|iq|ir|is|it|jm|jo|jp|ke|kg|kh|ki|km|kn|kp|kr|kw|ky|kz|la|lb|lc|li|lk|lr|ls|lt|lu|lv|ly|ma|mc|md|mg|mh|mil|mk|ml|mm|mn|mo|mp|mq|mr|ms|mt|mu|museum|mv|mw|mx|my|mz|na|name|nc|ne|net|nf|ng|ni|nl|no|np|nr|nt|nu|nz|om|org|pa|pe|pf|pg|ph|pk|pl|pm|pn|pr|pro|ps|pt|pw|py|qa|re|ro|ru|rw|sa|sb|sc|sd|se|sg|sh|si|sj|sk|sl|sm|sn|so|sr|st|su|sv|sy|sz|tc|td|tf|tg|th|tj|tk|tm|tn|to|tp|tr|tt|tv|tw|tz|ua|ug|uk|um|us|uy|uz|va|vc|ve|vg|vi|vn|vu|wf|ws|ye|yt|yu|za|zm|zw)$|(([0-9][0-9]?|[0-1][0-9][0-9]|[2][0-4][0-9]|[2][5][0-5])\.){3}([0-9][0-9]?|[0-1][0-9][0-9]|[2][0-4][0-9]|[2][5][0-5]))$/i"
                    ,$email));
        }
        ?>

</div>

I could change some details back on English but I'm sure you will know where the details are such as name.. email and etc.

And this is the CAPTCHA I got from the internet:

<?php

session_start();
$image_width = 120;
$image_height = 40;
$characters_on_image = 6;
$font = 'monofont.ttf';
$possible_letters = '23456789bcdfghjkmnpqrstvwxyz';

$code = '';


$i = 0;
while ($i < $characters_on_image) { 
$code .= substr($possible_letters, mt_rand(0, strlen($possible_letters)-1), 1);
$i++;
}


$font_size = $image_height * 0.75;
$image = @imagecreate($image_width, $image_height);


/* setting the background, text and noise colours here */
$background_color = imagecolorallocate($image, 255, 255, 255);
$text_color = imagecolorallocate($image, 20, 40, 100);
$image_noise_color = imagecolorallocate($image, 100, 120, 180);


/* generating the dots randomly in background */
for( $i=0; $i<($image_width*$image_height)/3; $i++ ) {
imagefilledellipse($image, mt_rand(0,$image_width), mt_rand(0,$image_height), 1, 1, $image_noise_color);
}


/* generating lines randomly in background of image */
for( $i=0; $i<($image_width*$image_height)/150; $i++ ) {
imageline($image, mt_rand(0,$image_width), mt_rand(0,$image_height), mt_rand(0,$image_width), mt_rand(0,$image_height), $image_noise_color);
}


/* create a text box and add 6 letters code in it */
$textbox = imagettfbbox($font_size, 0, $font, $code); 
$x = ($image_width - $textbox[4])/2;
$y = ($image_height - $textbox[5])/2;
imagettftext($image, $font_size, 0, $x, $y, $text_color, $font , $code);


/* Show captcha image in the page html page */
header('Content-Type: image/jpeg');// defining the image type to be shown in browser widow
imagejpeg($image);//showing the image
imagedestroy($image);//destroying the image instance
$_SESSION['6_letters_code'] = $code;
?>

It has also a small HTML included:

<HTML>
<HEAD><title>Contact Form</title></HEAD>
<BODY> 
<form method="POST" name="contact_form" action="result.php"> 
Enter Name: <input type="text" name="name"><br> 
Enter Message: <textarea name="message"></textarea><br>
<img src="captcha_code_file.php" /><br>
Enter captcha Code Here :<input id="6_letters_code" name="6_letters_code" type="text" ><br>
<input type="submit" value="Submit"><br>
</form>
</BODY>
</HTML>

And some small PHP too:

<?php 
session_start();
if( $_SESSION['6_letters_code'] == $_POST['6_letters_code'] && !empty($_SESSION['6_letters_code'] ) ) {
   echo 'You entered the correct code. Your message is successfully emailed.';
} else {
echo "Sorry, you have provided an invalid security code. Please <a href='contact_form_with_captcha.html'>CLICK HERE</a> to try again.";
}
?>

So I was wondering if you can tell me how to 'merge' this CAPTCHA to my actual contact form. So I want to have the same Contact Form but with this new CAPTCHA instead of having only one security question that can be easily be discovered by a single script and I would like to avoid spamming from bots.

Thanks a lot,

Fidel

[sneakyimp]

Put that first CAPTCHA code into a file called captcha_code_file.php in the same directory where your form lives.

Add this snip from the 2nd captcha bit (the form) to YOUR form:

<img src="captcha_code_file.php" /><br>
Enter captcha Code Here :<input id="6_letters_code" name="6_letters_code" type="text" >

And at that last bit of captcha PHP at the top of the page that handles your form submission.

[Fidel_Castro]

I already have that PHP names captcha_code_file.php.

But I wanted to know where should I put that code:

<img src="captcha_code_file.php" /><br>
Enter captcha Code Here :<input id="6_letters_code" name="6_letters_code" type="text" > 

Should I insert that code instead of the existing verification code or what?

And I'm quite sure that I should add the last PHP file too:

<?php
session_start();
if( $_SESSION['6_letters_code'] == $_POST['6_letters_code'] && !empty($_SESSION['6_letters_code'] ) ) {
   echo 'You entered the correct code. Your message is successfully emailed.';
} else {
echo "Sorry, you have provided an invalid security code. Please <a href='contact_form_with_captcha.html'>CLICK HERE</a> to try again.";
}
?> 

Because there is the message that should appear when the message is successfully sent and when a security error appeared.

[sneakyimp]

Like I said, the HTML bit should go into your form. Your form looks like quite a mess so I'm not really sure where. This HTML displays the captcha image and makes a text box for you to enter the code into:

<img src="captcha_code_file.php" /><br>
Enter captcha Code Here :<input id="6_letters_code" name="6_letters_code" type="text" >

I would probably put it right before the submit button.

As for the PHP that checks session, you need to probably alter the code a bit to integrate it into your form handling code. it basically says "if they submitted a form input named 6_letters_code and that code is correct, then echo 'you entered the correct code', otherwise say 'sorry the code is invalid' ". If you can't figure out where it goes in your code, then you probably need to do some PHP tutorials.