how to make an all text(q&a) captcha with php

[SKANK!!!!!]

the idea i cant find anything about it via google. so hence this post.
i want to have atleast 5 questions to ask that will be (key word: randomly) displayed when someone wants to reply. meaning the person has to answer correctly. i DO NOT WANT WHATS 5+5 KIND IF THING i want questions i create based on my site. question is to all of you:
HOW DO I DO IT? i know there has to be some kind of answer and question related thing to check it correctly but i havent a clue how to do it any ideas? SOLUTION? WHAT NOT? plz help me.

[somedude3488]

Captchas are annoying. You can easily just use form timeouts and tokens. They actually work better.

[SKANK!!!!!]

thank you but i still want to make this "captcha like" thing

[somedude3488]

Ok then. I have some old captcha code I found a while back. I modified it to work the way you want.

<?php

session_start();

class captcha {

	private $width = null;
	private $height = null;
	private $text = null;
	private $font = null;

	public function setWidth( $width ) {
		$this->width = $width;
	}

	public function setHeight( $height ) {
		$this->height = $height;
	}

	public function setText( $text ) {
		$this->text = $text;
	}

	public function setFont( $file ) {
		$this->font = $file;
	}

	function output() {
		foreach( array('width','height','text','font') as $var ) {
			if ( is_null( $this->$var ) ) {
				die("{$var} is null, please define a {$var}");
			}
		}
		$font_size = $this->height * 0.75;
		$image = @imagecreate($this->width, $this->height) or die('Cannot initialize new GD image stream');
		$background_color = imagecolorallocate($image, 255, 255, 204);
		$text_color = imagecolorallocate($image, 204, 0, 0);
		$noise_color = imagecolorallocate($image, 255, 102, 102);
		for( $i=0; $i<($this->width*$this->height)/3; $i++ ) {
			imagefilledellipse($image, mt_rand(0,$this->width), mt_rand(0,$this->height), 1, 1, $noise_color);
		}
		for( $i=0; $i<($this->width*$this->height)/150; $i++ ) {
			imageline($image, mt_rand(0,$this->width), mt_rand(0,$this->height), mt_rand(0,$this->width), mt_rand(0,$this->height), $noise_color);
		}
		$textbox = imagettfbbox($font_size, 0, $this->font, $this->text) or die('Error in imagettfbbox function');
		$x = ($this->width - $textbox[4])/2;
		$y = ($this->height - $textbox[5])/2;
		imagettftext($image, $font_size, 0, $x, $y, $text_color, $this->font , $this->text) or die('Error in imagettftext function');
		header('Content-Type: image/jpeg');
		imagejpeg($image);
		imagedestroy($image);
	}

}

$sentences = array(
	array(
		'text' => 'The color of the site background is?',
		'width' => 550,
		'answer' => 'grey'
	),
	array(
		'text' => 'Something like above?',
		'width' => 75,
		'answer' => '???'
	),
	array(
		'text' => 'AWeasdkfjasdfaiwefjasdfkjasdlfasdf?',
		'width' => 85,
		'answer' => '????'
	)
);

$i = mt_rand(0,( count( $sentences ) - 1 ));

$sentence =& $sentences[$i];

$captcha = new captcha;
$captcha->setHeight( 35 );
$captcha->setWidth( $sentence['width'] );
$captcha->setFont('monofont.ttf');
$captcha->setText( $sentence['text'] );

$_SESSION['sentence_answer'] = $sentence['answer'];

$captcha->output();

?>

You need to change the sentences and then change the width to match the length of the sentence. That will be trial and error.

[SKANK!!!!!]

ok that code is huge! thanks. but how do i do it without images only text.

[somedude3488]

Just echo the sentence to the page with a textbox. Then store the answer into a session.

I thought you were wanting a captcha like image with a sentence.

[SKANK!!!!!]

no image. store itin a session? how? i dont understand. there also has to be ATLEAST 5 QUESTIONS and it all has to RANDOMIZE.